TWI837205B - Laser processing device and laser processing method - Google Patents

Abstract

The laser processing device includes a support part, an irradiation part, and a control part. The irradiation part includes a shaping part, which shapes the laser light so that the shape of a part of the focusing area in a plane perpendicular to the optical axis of the laser light has a longitudinal direction. The control part includes: a determination part, which determines the longitudinal direction of the part of the focusing area when the part is relatively moved along the line, so that the longitudinal direction intersects with the moving direction of the part of the focusing area; and an adjustment part, which adjusts the longitudinal direction during the period of relatively moving the part of the focusing area along the line so that it becomes the direction determined by the determination part.

Description

Laser processing device and laser processing method

The present invention relates to a laser processing device and a laser processing method.

Patent document 1 describes a laser processing device, which has: a holding mechanism for holding a workpiece; and a laser light irradiation mechanism for irradiating laser light to the workpiece held by the holding mechanism. In the laser processing device described in Patent document 1, the laser light irradiation mechanism having a focusing lens is fixed to a base, and the movement of the workpiece in a direction perpendicular to the optical axis of the focusing lens is implemented by the holding mechanism. [Prior art document] [Patent document]

[Patent Document 1] Japanese Patent No. 5456510

[The problem that the invention wants to solve]

In addition, in the manufacturing process of semiconductor devices, for example, trimming is performed to remove the outer edge portion of a semiconductor wafer as an unnecessary portion. However, if the focal point of laser light is relatively moved along a line extending in a ring shape inside the outer edge of the object to remove the outer edge portion from the object and a modified area is formed along the line, the quality of the trimmed surface of the object from which the outer edge portion has been removed may be degraded depending on the location.

Therefore, one aspect of the present invention is to provide a laser processing device and a laser processing method that can suppress the situation where the quality of the trimmed surface of an object with the outer edge portion removed is reduced depending on the location. [Means for solving the problem]

A laser processing device according to one embodiment of the present invention is a laser processing device that forms a modified area on an object by irradiating laser light with at least a portion of a focusing area that matches an object, and is characterized by comprising: a support portion that supports the object; an irradiation portion that irradiates laser light to the object supported by the support portion; and a control portion that controls the support portion and the irradiation portion, wherein the irradiation portion has a shaping portion that shapes the laser light so that a portion of the focusing area within a plane perpendicular to the optical axis of the laser light has a longitudinal direction, and the control portion is The invention comprises: a determining unit, which determines the orientation in the length direction of the case where a part of the focusing area is relatively moved along the line based on object information about the object and line information about the line extending in a ring shape on the inner side of the outer edge of the object so that the length direction intersects with the moving direction of the part of the focusing area; and an adjusting unit, which adjusts the orientation in the length direction during the period of relatively moving the part of the focusing area along the line so that the orientation becomes the orientation determined by the determining unit.

In this laser processing device, while a part of the focusing area is relatively moved along a line, the orientation in the longitudinal direction of the shape of a part of the focusing area in a plane perpendicular to the optical axis of the laser light (hereinafter also referred to as the "beam shape") is adjusted to an orientation that intersects with the moving direction of the part of the focusing area (hereinafter also referred to as the processing direction), that is, an orientation determined based on the object information and the line information. Therefore, only when the longitudinal direction of the beam shape is consistent with the processing direction, a part of the focusing area is relatively moved along the line, so that even if the quality of the trimmed surface is degraded depending on the part due to the physical properties of the object, the deterioration of the quality of the trimmed surface can be suppressed. This can suppress the deterioration of the quality of the trimmed surface of the object from which the outer edge portion has been removed depending on the part.

In one aspect of the laser processing device of the present invention, the object information may include information on the crystal orientation of the object, and the line information may include information on the moving direction of a part of the focusing area. Thus, even if the object has a crystal orientation, it is possible to suppress the quality of the trimmed surface of the object from being reduced depending on the location.

In one aspect of the laser processing device of the present invention, the shaping unit may include a spatial light modulator, and the adjusting unit may adjust the longitudinal direction by controlling the spatial light modulator, thereby accurately adjusting the longitudinal direction of the shape of a part of the focusing area in a plane perpendicular to the optical axis of the laser light.

In the laser processing device of one aspect of the present invention, the determining unit may determine the first orientation in the longitudinal direction when a part of the light-collecting area is relatively moved along the first area of the line, and the second orientation in the longitudinal direction when a part of the light-collecting area is relatively moved along the second area of the line, and the adjusting unit may adjust the orientation in the longitudinal direction to the first orientation when a part of the light-collecting area is located in the first area, and adjust the orientation in the longitudinal direction to the second orientation when a part of the light-collecting area is located in the second area during the period of relatively moving the part of the light-collecting area along the line. In this way, the quality of the trimmed surface of the object in the first area and the second area may be more reliably suppressed from being degraded.

In one embodiment of the laser processing device of the present invention, the target object is a wafer having a (100) plane as the main plane, a first crystal orientation perpendicular to the (110) plane on one side and a second crystal orientation perpendicular to the (110) plane on the other side. The line extends in a circular ring shape when viewed from a direction perpendicular to the main plane. The first region is a region in which the angle of the movement direction of a part of the focusing area to the first crystal orientation, that is, the processing angle, is greater than 0° and less than 45° when a part of the focusing area is relatively moved along the line. The second region is a region in which the processing angle is greater than 45° and less than 90° when a part of the focusing area is relatively moved along the line. Thereby, even when the object is a wafer having a (100) plane as a main surface, it is possible to suppress the quality of the trimmed surface of the object from being degraded depending on the location.

In a laser processing device of one aspect of the present invention, the first orientation and the second orientation may be directions inclined with respect to the moving direction so as to be close to the direction with a larger angle formed between the first crystal orientation and the second crystal orientation. Thus, even when the object is a wafer having a (100) plane as a main surface, it is possible to more reliably suppress the degradation of the quality of the trimmed surface of the object in the first region and the second region.

In a laser processing device of one aspect of the present invention, the first orientation and the second orientation may be an orientation inclined by 10° to 35° from the moving direction in such a manner that the first crystal orientation and the second crystal orientation are close to the direction with a larger angle with the moving direction. Thus, even when the object is a wafer with a (100) plane as the main surface, it is possible to more reliably suppress the degradation of the trimmed surface of the object in the first region and the second region.

In the laser processing device of the present invention, the adjustment section can adjust the longitudinal direction in a continuously changing manner while relatively moving a part of the focusing area along the line. This can more reliably suppress the quality reduction of the trimmed surface of the object at each part of the line.

In a laser processing device of one aspect of the present invention, the object may be a wafer having a (100) plane as a main surface, a first crystal orientation perpendicular to one (110) plane and a second crystal orientation perpendicular to the other (110) plane, the determining unit determines the orientation in the length direction of the case where a part of the focusing area is relatively moved along the line, with respect to the angle of the moving direction of a part of each focusing area to the first crystal orientation, that is, the processing angle, and the adjusting unit continuously changes the orientation determined by the determining unit in accordance with the processing angle while the part of the focusing area is relatively moved along the line. Thus, even when the object is a wafer having a (100) plane as a main surface, it is possible to more reliably suppress the quality of the trimmed surface of the object from being degraded at each part of the line.

A laser processing method according to one aspect of the present invention is a laser processing method for forming a modified area in an object by irradiating laser light with at least a portion of a focusing area in cooperation with an object, and is characterized by comprising: a determination process for determining the orientation in the length direction of the case where a portion of the focusing area is relatively moved along a line based on object information about the object and line information about a line extending in a ring shape on the inner side of an outer edge of the object so that the length direction of the shape of a portion of the focusing area in a plane perpendicular to the optical axis of the laser light intersects with the moving direction of the portion of the focusing area; and an adjustment process for adjusting the orientation in the length direction while a portion of the focusing area is relatively moved along the line so that the orientation becomes the determined orientation.

In this laser processing method, while a part of the focusing area is relatively moved along the line, the longitudinal direction of the beam shape is adjusted to an orientation that intersects the processing direction, that is, an orientation determined according to the object information and the line information. Therefore, only when the longitudinal direction of the beam shape is consistent with the processing direction, a part of the focusing area is relatively moved along the line, so that in the case where the quality of the trimmed surface is reduced depending on the part due to the physical properties of the object, for example, the quality reduction of the trimmed surface can be suppressed. Because the quality of the trimmed surface of the object with the outer edge portion removed is reduced depending on the part, it can be suppressed. [Effect of the invention]

According to one aspect of the present invention, it is possible to provide a laser processing device and a laser processing method that can suppress the situation where the quality of the trimmed surface of an object from which the outer edge portion has been removed is degraded depending on the location.

Hereinafter, the embodiments will be described in detail with reference to the drawings, etc. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and repeated descriptions will be omitted.

First, the basic structure, effects, and variations of the laser processing device are described.

[Structure of laser processing device] As shown in FIG1 , the laser processing device 1 has a plurality of moving mechanisms 5, 6; a support portion 7; a pair of laser processing heads (first laser processing head, second laser processing head) 10A, 10B; a light source unit 8; and a control portion 9. In the following description, the first direction is referred to as the X direction, the second direction perpendicular to the first direction is referred to as the Y direction, and the third direction perpendicular to the first direction and the second direction is referred to as the Z direction. In the present embodiment, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction.

The moving mechanism 5 includes a fixed portion 51, a moving portion 53, and a mounting portion 55. The fixed portion 51 is mounted on the device frame 1a. The moving portion 53 is mounted on a track provided on the fixed portion 51 and is movable in the Y direction. The mounting portion 55 is mounted on a track provided on the moving portion 53 and is movable in the X direction.

The moving mechanism 6 has a fixed portion 61; a pair of moving portions (a first moving portion and a second moving portion) 63, 64; and a pair of mounting portions (a first mounting portion and a second mounting portion) 65, 66. The fixed portion 61 is mounted on the device frame 1a. The pair of moving portions 63, 64 are respectively mounted on rails provided on the fixed portion 61, and are each independently movable in the Y direction. The mounting portion 65 is mounted on the rail provided on the moving portion 63, and is movable in the Z direction. The mounting portion 66 is mounted on the rail provided on the moving portion 64, and is movable in the Z direction. That is, with respect to the device frame 1a, a pair of mounting portions 65, 66 are movable in the Y direction and the Z direction, respectively. The moving portions 63, 64 constitute the first and second horizontal moving mechanisms (horizontal moving mechanisms), respectively. The mounting portions 65 and 66 constitute the first and second vertical movement mechanisms (vertical movement mechanisms), respectively.

The support part 7 is mounted on the rotation axis of the mounting part 55 provided on the moving mechanism 5, and can rotate with the axis parallel to the Z direction as the center line. That is, the support part 7 can move along the X direction and the Y direction respectively, and can rotate with the axis parallel to the Z direction as the center line. The support part 7 is used to support the object 100. The object 100 is, for example, a wafer.

As shown in FIG. 1 and FIG. 2 , the laser processing head 10A is mounted on the mounting portion 65 of the moving mechanism 6. The laser processing head 10A irradiates the object 100 supported by the support portion 7 with laser light L1 (also referred to as "first laser light L1") while being opposed to the support portion 7 in the Z direction. The laser processing head 10B is mounted on the mounting portion 66 of the moving mechanism 6. The laser processing head 10B irradiates the object 100 supported by the support portion 7 with laser light L2 (also referred to as "second laser light L2") while being opposed to the support portion 7 in the Z direction. The laser processing heads 10A and 10B constitute an irradiation portion.

The light source unit 8 has a pair of light sources 81 and 82. The light source 81 outputs laser light L1. The laser light L1 is emitted from the emission portion 81a of the light source 81 and guided to the laser processing head 10A through the optical fiber 2. The light source 82 outputs laser light L2. The laser light L2 is emitted from the emission portion 82a of the light source 82 and guided to the laser processing head 10B through the other optical fiber 2.

The control unit 9 is used to control the various parts of the laser processing device 1 (supporting part 7, multiple moving mechanisms 5, 6, a pair of laser processing heads 10A, 10B, and light source unit 8, etc.). The control unit 9 is composed of a computer device including a processor, a memory, a storage, and a communication device. In the control unit 9, the software (program) loaded on the memory, etc. is executed by the processor, and the reading and writing of data in the memory and storage and the communication through the communication device are controlled by the processor. In this way, the control unit 9 can achieve various functions.

An example of processing performed by the laser processing apparatus 1 configured as above will be described. The example of processing is an example of forming a modified region inside the object 100 along a plurality of lines arranged in a grid shape in order to cut the object 100 as a wafer into a plurality of chips.

First, the moving mechanism 5 moves the support 7 in the X direction and the Y direction respectively, so that the support 7 supporting the object 100 faces the pair of laser processing heads 10A and 10B in the Z direction. Then, the moving mechanism 5 rotates the support 7 with an axis parallel to the Z direction as the center line, so that a plurality of lines extending in one direction on the object 100 are along the X direction.

Then, the moving mechanism 6 moves the laser processing head 10A along the Y direction so that the focal point (a part of the focal area) of the laser light L1 is located on a line extending in one direction. In addition, in order to make the focal point of the laser light L2 located on another line extending in one direction, the moving mechanism 6 moves the laser processing head 10B along the Y direction. Then, the moving mechanism 6 moves the laser processing head 10A along the Z direction so that the focal point of the laser light L1 is located inside the object 100. In addition, the moving mechanism 6 moves the laser processing head 10B along the Z direction so that the focal point of the laser light L2 is located inside the object 100.

Then, the light source 81 outputs the laser light L1 and the laser processing head 10A irradiates the laser light L1 to the object 100, and the light source 82 outputs the laser light L2 and the laser processing head 10B irradiates the laser light L2 to the object 100. At the same time, the moving mechanism 5 moves the support 7 along the X direction, so that the focal point of the laser light L1 moves relatively along a line extending in one direction, and the focal point of the laser light L2 moves relatively along other lines extending in one direction. In this way, the laser processing device 1 forms a modified area inside the object 100 along a plurality of lines extending in one direction in the object 100.

Next, the moving mechanism 5 rotates the support portion 7 with the axis parallel to the Z direction as the center line so that a plurality of lines extending in another direction perpendicular to the one direction on the object 100 are along the X direction.

Then, the moving mechanism 6 moves the laser processing head 10A along the Y direction so that the focal point of the laser light L1 is located on a line extending in another direction. In addition, in order to make the focal point of the laser light L2 located on another line extending in another direction, the moving mechanism 6 moves the laser processing head 10B along the Y direction. Then, the moving mechanism 6 moves the laser processing head 10A along the Z direction so that the focal point of the laser light L1 is located inside the object 100. In addition, the moving mechanism 6 moves the laser processing head 10B along the Z direction so that the focal point of the laser light L2 is located inside the object 100.

Then, the light source 81 outputs the laser light L1 and the laser processing head 10A irradiates the laser light L1 to the object 100, and the light source 82 outputs the laser light L2 and the laser processing head 10B irradiates the laser light L2 to the object 100. At the same time, the moving mechanism 5 moves the support 7 along the X direction, moves the focal point of the laser light L1 relatively along a line extending in another direction, and moves the focal point of the laser light L2 relatively along other lines extending in another direction. In this way, the laser processing device 1 forms a modified area inside the object 100 along a plurality of lines extending in another direction orthogonal to the one direction.

Furthermore, in an example of the aforementioned processing, the light source 81 outputs a laser light L1 having transparency to the object 100 by, for example, a pulse oscillation method, and the light source 82 outputs a laser light L2 having transparency to the object 100 by, for example, a pulse oscillation method. If such laser light is focused inside the object 100, then in the portion corresponding to the focal point of the laser light, in particular, the laser light is absorbed, and a modified region is formed inside the object 100. The modified region is a region whose density, refractive index, mechanical strength, other physical properties, etc. are different from the surrounding non-modified regions. The modified region includes, for example, a melt-processed region, a cracked region, an insulation-damaged region, a refractive index-changed region, and the like.

Laser light outputted by pulse oscillation is irradiated onto the object 100. If the focal point of the laser light is relatively moved along a line set on the object 100, a plurality of modified points are formed and arranged in a row along the line. One modified point is formed by irradiation with one pulse of laser light. A row of modified areas is a collection of a plurality of modified points arranged in a row. Adjacent modified points exist in a connected or separated situation by the relative moving speed of the focal point of the laser light to the object 100 and the repetition frequency of the laser light. The shape of the set line is not limited to a grid shape, and may also be a ring shape, a straight line shape, a curve shape, or a combination of at least some of these shapes. [Structure of laser processing head]

As shown in FIG. 3 and FIG. 4 , the laser machining head 10A includes a housing 11 , an incident portion 12 , an adjustment portion 13 , and a focusing portion 14 .

The frame 11 has a first wall 21 and a second wall 22, a third wall 23 and a fourth wall 24, and a fifth wall 25 and a sixth wall 26. The first wall 21 and the second wall 22 are opposed to each other in the X direction. The third wall 23 and the fourth wall 24 are opposed to each other in the Y direction. The fifth wall 25 and the sixth wall 26 are opposed to each other in the Z direction.

The distance between the third wall portion 23 and the fourth wall portion 24 is smaller than the distance between the first wall portion 21 and the second wall portion 22. The distance between the first wall portion 21 and the second wall portion 22 is smaller than the distance between the fifth wall portion 25 and the sixth wall portion 26. Furthermore, the distance between the first wall portion 21 and the second wall portion 22 may be equal to the distance between the fifth wall portion 25 and the sixth wall portion 26, or may be larger than the distance between the fifth wall portion 25 and the sixth wall portion 26.

In the laser processing head 10A, the first wall portion 21 is located on the fixed portion 61 side of the moving mechanism 6, and the second wall portion 22 is located on the opposite side of the fixed portion 61. The third wall portion 23 is located on the mounting portion 65 side of the moving mechanism 6, and the fourth wall portion 24 is located on the opposite side of the mounting portion 65, that is, on the laser processing head 10B side (see FIG. 2). The fifth wall portion 25 is located on the opposite side of the support portion 7, and the sixth wall portion 26 is located on the support portion 7 side.

The frame 11 is mounted on the mounting portion 65 when the third wall portion 23 is arranged on the mounting portion 65 side of the moving mechanism 6. Specifically, it is as follows. The mounting portion 65 has a seat plate 65a and a mounting plate 65b. The seat plate 65a is mounted on a rail provided on the moving portion 63 (refer to FIG. 2). The mounting plate 65b is erected on the end of the seat plate 65a on the laser processing head 10B side (refer to FIG. 2). The frame 11 is mounted on the mounting portion 65 by screwing the bolt 28 into the mounting plate 65b via the pedestal 27 when the third wall portion 23 contacts the mounting plate 65b. The pedestal 27 is provided on the first wall portion 21 and the second wall portion 22, respectively. The frame 11 can be loaded and unloaded with respect to the mounting portion 65.

The incident portion 12 is mounted on the fifth wall portion 25. The incident portion 12 injects the laser light L1 into the frame 11. The incident portion 12 is close to the second wall portion 22 side (one wall side) in the X direction and close to the fourth wall portion 24 side in the Y direction. That is, the distance between the incident portion 12 and the second wall portion 22 in the X direction is smaller than the distance between the incident portion 12 and the first wall portion 21 in the X direction, and the distance between the incident portion 12 and the fourth wall portion 24 in the Y direction is smaller than the distance between the incident portion 12 and the third wall portion 23 in the X direction.

The incident portion 12 is configured to be connectable to the connection end 2a of the optical fiber 2. The connection end 2a of the optical fiber 2 is provided with a collimating lens for collimating the laser light L1 emitted from the emission end of the optical fiber, and no isolator for suppressing the return light is provided. The isolator is provided near the optical fiber closer to the light source 81 side than the connection end 2a. In this way, the miniaturization of the connection end 2a can be sought, and the miniaturization of the incident portion 12 can be sought. Furthermore, the isolator can also be provided at the connection end 2a of the optical fiber 2.

The adjustment section 13 is disposed in the frame 11. The adjustment section 13 is used to adjust the laser light L1 incident from the incident section 12. The various structures of the adjustment section 13 are mounted on the optical base 29 provided in the frame 11. The optical base 29 is mounted on the frame 11 in such a manner that the area in the frame 11 is divided into an area on the third wall 23 side and an area on the fourth wall 24 side. The optical base 29 is formed integrally with the frame 11. The details of the various structures of the adjustment section 13 mounted on the optical base 29 on the fourth wall 24 side will be described later.

The light-collecting portion 14 is disposed on the sixth wall portion 26. Specifically, the light-collecting portion 14 is disposed on the sixth wall portion 26 in a state of being inserted through a hole 26a formed in the sixth wall portion 26. The light-collecting portion 14 collects the laser light L1 adjusted by the adjusting portion 13 and emits it out of the frame 11. The light-collecting portion 14 is close to the second wall portion 22 side (one wall side) in the X direction and close to the fourth wall portion 24 side in the Y direction. That is, the distance between the light-collecting portion 14 and the second wall portion 22 in the X direction is smaller than the distance between the light-collecting portion 14 and the first wall portion 21 in the X direction, and the distance between the light-collecting portion 14 and the fourth wall portion 24 in the Y direction is smaller than the distance between the light-collecting portion 14 and the third wall portion 23 in the X direction.

As shown in FIG5 , the adjustment section 13 has an attenuator 31, a beam expander 32, and a mirror 33. The incident section 12, and the attenuator 31, the beam expander 32, and the mirror 33 of the adjustment section 13 are arranged on a straight line (first straight line) A1 extending along the Z direction. The attenuator 31 and the beam expander 32 are arranged on the straight line A1 between the incident section 12 and the mirror 33. The attenuator 31 is used to adjust the output of the laser light L1 incident from the incident section 12. The beam expander 32 expands the diameter of the laser light L1 whose output is adjusted by the attenuator 31. The mirror 33 is used to reflect the laser light L1 whose diameter is expanded by the beam expander 32.

The adjustment section 13 also has a reflective spatial light modulator 34 and an imaging optical system 35. The reflective spatial light modulator 34 and the imaging optical system 35 of the adjustment section 13, and the focusing section 14 are arranged on a straight line (second straight line) A2 extending along the Z direction. The reflective spatial light modulator 34 modulates the laser light L1 reflected by the mirror 33. The reflective spatial light modulator 34 is, for example, a spatial light modulator (SLM: Spatial Light Modulator) of a reflective liquid crystal (LCOS: Liquid Crystal on Silicon). The imaging optical system 35 is a bilateral telecentric optical system in which the reflecting surface 34a of the reflective spatial light modulator 34 and the entrance pupil surface 14a of the focusing section 14 are in an imaging relationship. The imaging optical system 35 is composed of three or more lenses.

Straight line A1 and straight line A2 are located on a plane perpendicular to the Y direction. Straight line A1 is opposite to straight line A2 and is located on the side of the second wall portion 22 (the side of one wall portion). In the laser processing head 10A, the laser light L1 is incident from the incident portion 12 into the frame 11 and then travels on the straight line A1. After being reflected by the mirror 33 and the reflective spatial light modulator 34 in sequence, it travels on the straight line A2 and is emitted from the focusing portion 14 to the outside of the frame 11. Furthermore, the arrangement order of the attenuator 31 and the beam expander 32 may also be reversed. Furthermore, the attenuator 31 may also be arranged between the mirror 33 and the reflective spatial light modulator 34. Furthermore, the adjustment portion 13 may also have other optical components (for example, a turning mirror arranged in front of the beam expander 32).

The laser processing head 10A further includes a spectroscope 15 , a measuring unit 16 , an observation unit 17 , a driving unit 18 , and a circuit unit 19 .

The spectroscope 15 is disposed on the straight line A2 between the imaging optical system 35 and the focusing section 14. That is, the spectroscope 15 is disposed between the adjustment section 13 and the focusing section 14 in the frame 11. The spectroscope 15 is mounted on the optical base 29 on the side of the fourth wall 24. The spectroscope 15 allows the laser light L1 to pass through. From the viewpoint of suppressing astigmatism, the spectroscope 15 may be, for example, a cubic shape or may be a two-plate type disposed in a twisted relationship.

The measuring section 16 is arranged on the first wall 21 side (the side opposite to the wall side) with respect to the adjusting section 13 in the frame 11. The measuring section 16 is mounted on the optical base 29 on the fourth wall 24 side. The measuring section 16 outputs a measuring light L10 for measuring the distance between the surface of the object 100 (for example, the surface on the side where the laser light L1 is incident) and the focusing section 14, and detects the measuring light L10 reflected by the surface of the object 100 through the focusing section 14. That is, the measuring light L10 output from the measuring section 16 is irradiated to the surface of the object 100 through the focusing section 14, and the measuring light L10 reflected by the surface of the object 100 is detected by the measuring section 16 through the focusing section 14.

More specifically, the measurement light L10 output from the measurement section 16 is reflected in sequence by the beam splitter 20 and the spectroscope 15 mounted on the optical base 29 on the side of the fourth wall 24, and then emitted from the focusing section 14 to the outside of the frame 11. The measurement light L10 reflected by the surface of the object 100 is incident from the focusing section 14 into the frame 11, and then reflected in sequence by the spectroscope 15 and the beam splitter 20, and then incident on the measurement section 16 and detected by the measurement section 16.

The observation section 17 is disposed on the first wall 21 side (the side opposite to the wall side) with respect to the adjustment section 13 in the frame 11. The observation section 17 is mounted on the optical base 29 on the fourth wall 24 side. The observation section 17 outputs the observation light L20 for observing the surface of the object 100 (for example, the surface on the side where the laser light L1 is incident), and detects the observation light L20 reflected by the surface of the object 100 through the focusing section 14. That is, the observation light L20 output from the observation section 17 is irradiated to the surface of the object 100 through the focusing section 14, and the observation light L20 reflected by the surface of the object 100 is detected by the observation section 17 through the focusing section 14.

More specifically, the observation light L20 output from the observation section 17 passes through the beam splitter 20, is reflected by the spectroscope 15, and is then emitted from the focusing section 14 to the outside of the frame 11. The observation light L20 reflected by the surface of the object 100 enters the frame 11 from the focusing section 14, is reflected by the spectroscope 15, and then passes through the beam splitter 20 to enter the observation section 17 and is detected by the observation section 17. Furthermore, the wavelengths of the laser light L1, the measurement light L10, and the observation light L20 are different from each other (at least the central wavelengths of each are offset from each other).

The driving unit 18 is mounted on the optical base 29 on the side of the fourth wall 24. It is mounted on the sixth wall 26 of the frame 11. The driving unit 18 moves the focusing unit 14 disposed on the sixth wall 26 along the Z direction by the driving force of a piezoelectric element, for example.

The circuit section 19 is disposed in the frame 11 on the side of the third wall 23 with respect to the optical base 29. That is, the circuit section 19 is disposed in the frame 11 on the side of the third wall 23 with respect to the adjustment section 13, the measuring section 16 and the observation section 17. The circuit section 19 is, for example, a plurality of circuit substrates. The circuit section 19 processes the signal output from the measuring section 16 and the signal input to the reflective spatial light modulator 34. The circuit section 19 controls the driving section 18 based on the signal output from the measuring section 16. As an example, the circuit section 19 controls the driving section 18 based on the signal output from the measuring section 16 so that the distance between the surface of the object 100 and the focusing section 14 is maintained constant (that is, the distance between the surface of the object 100 and the focusing point of the laser light L1 is maintained constant). Furthermore, the housing 11 is provided with a connector (not shown) to which wiring for electrically connecting the circuit section 19 to the control section 9 (see FIG. 1 ) and the like is connected.

The laser processing head 10B is similar to the laser processing head 10A, and includes a housing 11, an incident portion 12, an adjustment portion 13, a focusing portion 14, a spectroscope 15, a measuring portion 16, an observation portion 17, a driving portion 18, and a circuit portion 19. However, the structures of the laser processing head 10B are arranged to have a plane-symmetrical relationship with the structures of the laser processing head 10A with respect to a virtual plane passing through the center point between a pair of mounting portions 65 and 66 and perpendicular to the Y direction, as shown in FIG.

For example, the frame (first frame) 11 of the laser machining head 10A is mounted on the mounting portion 65 in such a manner that the fourth wall portion 24 is located on the laser machining head 10B side with respect to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side with respect to the fifth wall portion 25. In contrast, the frame (second frame) 11 of the laser machining head 10B is mounted on the mounting portion 66 in such a manner that the fourth wall portion 24 is located on the laser machining head 10A side with respect to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side with respect to the fifth wall portion 25.

The frame 11 of the laser processing head 10B is configured to be mounted on the mounting portion 66 when the third wall portion 23 is arranged on the mounting portion 66 side. Specifically, it is as follows. The mounting portion 66 has a seat plate 66a and a mounting plate 66b. The seat plate 66a is mounted on a rail provided on the moving portion 63. The mounting plate 66b is erected on the end of the seat plate 66a on the laser processing head 10A side. The frame 11 of the laser processing head 10B is mounted on the mounting portion 66 when the third wall portion 23 contacts the mounting plate 66b. The frame 11 of the laser processing head 10B can be loaded and unloaded on the mounting portion 66. [Function and Effect]

In the laser processing head 10A, since the light source for outputting the laser light L1 is not provided in the frame 11, the frame 11 can be miniaturized. In addition, in the frame 11, the distance between the third wall portion 23 and the fourth wall portion 24 is smaller than the distance between the first wall portion 21 and the second wall portion 22, and the light focusing portion 14 disposed on the sixth wall portion 26 is offset toward the fourth wall portion 24 in the Y direction. Thus, when the frame 11 is moved in a direction perpendicular to the optical axis of the light focusing portion 14, even if there is another component (such as the laser processing head 10B) on the fourth wall portion 24 side, the light focusing portion 14 can be brought close to the other component. Therefore, the laser processing head 10A is ideally suitable for moving the light focusing portion 14 in a direction perpendicular to its optical axis.

In the laser processing head 10A, the incident portion 12 is provided on the fifth wall portion 25 and is offset in the Y direction toward the fourth wall portion 24. Thus, other components (such as the circuit portion 19) can be arranged in the region of the region within the frame 11 that is closer to the third wall portion 23 than the adjustment portion 13, and the region can be effectively utilized.

In the laser processing head 10A, the focusing part 14 is offset in the X direction toward the second wall part 22. Thus, when the frame 11 is moved in a direction perpendicular to the optical axis of the focusing part 14, even if there are other components on the second wall part 22, for example, the focusing part 14 can be brought close to the other components.

In the laser processing head 10A, the incident portion 12 is provided on the fifth wall portion 25 and is offset in the X direction toward the second wall portion 22. Thus, other components (such as the measuring portion 16 and the observation portion 17) can be arranged in the region of the region within the frame 11 that is closer to the first wall portion 21 than the adjustment portion 13, and the region can be effectively utilized.

Furthermore, in the laser processing head 10A, the measuring section 16 and the observation section 17 are arranged in the area inside the frame 11, on the side of the first wall section 21 with respect to the adjusting section 13, the circuit section 19 is arranged in the area inside the frame 11, on the side of the third wall section 23 with respect to the adjusting section 13, and the spectroscope 15 is arranged in the frame 11, between the adjusting section 13 and the focusing section 14. Thus, the area inside the frame 11 can be effectively utilized. Furthermore, in the laser processing device 1, processing can be performed based on the measurement result of the distance between the surface of the object 100 and the focusing section 14. Furthermore, in the laser processing device 1, processing can be performed based on the observation result of the surface of the object 100.

In the laser processing head 10A, the circuit section 19 controls the driving section 18 according to the signal output from the measuring section 16. Thus, the position of the focal point of the laser light L1 can be adjusted according to the measurement result of the distance between the surface of the object 100 and the focusing section 14.

In the laser processing head 10A, the incident part 12, the attenuator 31, the beam expander 32 and the mirror 33 of the adjustment part 13 are arranged on the straight line A1 extending along the Z direction, and the reflective spatial light modulator 34, the imaging optical system 35 and the focusing part 14 of the adjustment part 13, and the focusing part 14 are arranged on the straight line A2 extending along the Z direction. In this way, the adjustment part 13 having the attenuator 31, the beam expander 32, the reflective spatial light modulator 34 and the imaging optical system 35 can be compactly configured.

In the laser processing head 10A, the straight line A1 is opposite to the straight line A2 and is located on the second wall portion 22 side. Thus, in the region within the frame 11, other optical systems (such as the measuring section 16 and the observing section 17) using the focusing section 14 can be configured in the region closer to the first wall portion 21 than the adjusting section 13, thereby increasing the degree of freedom of the structure of the other optical systems.

The above functions and effects can also be achieved by the laser processing head 10B.

In the laser processing device 1, the focusing portion 14 of the laser processing head 10A is offset toward the laser processing head 10B side at the frame 11 of the laser processing head 10A, and the focusing portion 14 of the laser processing head 10B is offset toward the laser processing head 10A side at the frame 11 of the laser processing head 10B. Thus, when the pair of laser processing heads 10A and 10B are moved in the Y direction, the focusing portion 14 of the laser processing head 10A and the focusing portion 14 of the laser processing head 10B can be brought close to each other. Therefore, according to the laser processing device 1, the object 100 can be processed efficiently.

Furthermore, in the laser processing device 1, the pair of mounting parts 65 and 66 can be moved in the Y direction and the Z direction, respectively. Thus, the object 100 can be processed more efficiently.

Furthermore, in the laser processing device 1, the support portion 7 can be moved in the X direction and the Y direction, respectively, and rotated with an axis parallel to the Z direction as the center line. Thus, the object 100 can be processed more efficiently. [Variation]

For example, as shown in FIG6 , the incident part 12, the adjustment part 13, and the focusing part 14 may be arranged on a straight line A extending along the Z direction. In this way, the adjustment part 13 can be compactly configured. In this case, the adjustment part 13 may not have the reflective spatial light modulator 34 and the imaging optical system 35. In addition, the adjustment part 13 may have the attenuator 31 and the beam expander 32. In this way, the adjustment part 13 having the attenuator 31 and the beam expander 32 can be compactly configured. Furthermore, the arrangement order of the attenuator 31 and the beam expander 32 may be reversed.

Furthermore, the frame 11 is configured such that at least one of the first wall portion 21, the second wall portion 22, the third wall portion 23, and the fifth wall portion 25 is arranged on the side of the mounting portion 65 (or the mounting portion 66) of the laser processing device 1, and the frame 11 can be mounted on the mounting portion 65 (or the mounting portion 66). Furthermore, the focusing portion 14 can be offset toward the fourth wall portion 24 at least in the Y direction. Thereby, when the frame 11 is moved along the Y direction, even if there are other components on the side of the fourth wall portion 24, for example, the focusing portion 14 can be brought close to the other components. Furthermore, when the frame 11 is moved along the Z direction, for example, the focusing portion 14 can be brought close to the object 100.

Furthermore, the light-collecting portion 14 may be offset toward the first wall portion 21 at least in the X direction. Thus, when the frame 11 is moved in a direction perpendicular to the optical axis of the light-collecting portion 14, even if there are other components on the first wall portion 21 side, for example, the light-collecting portion 14 can be brought close to the other components. In this case, the incident portion 12 may be offset toward the first wall portion 21 side in the X direction. Thus, other components (for example, the measuring portion 16 and the observing portion 17) can be arranged in the region within the frame 11 that is closer to the second wall portion 22 than the adjusting portion 13, and the region can be effectively utilized.

Furthermore, at least one of the guiding of the laser light L1 from the emitting portion 81a of the light source unit 8 to the incident portion 12 of the laser processing head 10A and the guiding of the laser light L2 from the emitting portion 82a of the light source unit 8 to the incident portion 12 of the laser processing head 10B may be implemented by a mirror. FIG7 is a front view of a portion of the laser processing device 1 in which the laser light L1 is guided by a mirror. In the structure shown in FIG7, the mirror 3 for reflecting the laser light L1 is mounted on the moving portion 63 of the moving mechanism 6 in such a manner as to be opposite to the emitting portion 81a of the light source unit 8 in the Y direction and to be opposite to the incident portion 12 of the laser processing head 10A in the Z direction.

In the structure shown in FIG. 7 , even if the moving portion 63 of the moving mechanism 6 is moved in the Y direction, the state in which the mirror 3 is opposed to the emission portion 81a of the light source unit 8 in the Y direction is maintained. Furthermore, even if the mounting portion 65 of the moving mechanism 6 is moved in the Z direction, the state in which the mirror 3 is opposed to the injection portion 12 of the laser processing head 10A in the Z direction is maintained. Therefore, the laser light L1 emitted from the emission portion 81a of the light source unit 8 can be reliably injected into the injection portion 12 of the laser processing head 10A without being affected by the position of the laser processing head 10A. In addition, a light source such as a high-output long and short pulse laser, which is extremely difficult to guide through the optical fiber 2, can also be used.

7, the mirror 3 may be mounted on the moving portion 63 of the moving mechanism 6 in a manner that allows at least one of angle adjustment and position adjustment. This allows the laser light L1 emitted from the emission portion 81a of the light source unit 8 to be more reliably emitted into the injection portion 12 of the laser processing head 10A.

Furthermore, the light source unit 8 may include one light source. In this case, the light source unit 8 may be configured to emit a portion of the laser light output from one light source from the emission portion 81a and to emit the remaining portion of the laser light from the emission portion 82b.

Furthermore, the laser processing device 1 may also include a laser processing head 10A. Even in the case of a laser processing device 1 including a laser processing head 10A, when the frame 11 is moved in the Y direction perpendicular to the optical axis of the focusing portion 14, even if there are other components on the side of the fourth wall portion 24, for example, the focusing portion 14 can be brought close to the other components. Therefore, according to the laser processing device 1 including a laser processing head 10A, the object 100 can be processed efficiently. Furthermore, in the laser processing device 1 including a laser processing head 10A, when the mounting portion 65 is moved in the Z direction, the object 100 can be processed efficiently. Furthermore, in the laser processing apparatus 1 including one laser processing head 10A, if the support portion 7 moves in the X direction and rotates about an axis parallel to the Z direction as a center line, the object 100 can be processed more efficiently.

Furthermore, the laser processing device 1 may also have more than three laser processing heads. FIG8 is a perspective view of the laser processing device 1 having two pairs of laser processing heads. The laser processing device 1 shown in FIG8 has a plurality of moving mechanisms 200, 300, 400; a support portion 7; a pair of laser processing heads 10A, 10B; a pair of laser processing heads 10C, 10D; and a light source unit (not shown).

The moving mechanism 200 moves the support portion 7 in the X direction, the Y direction, and the Z direction, and rotates the support portion 7 with an axis parallel to the Z direction as a center line.

The moving mechanism 300 includes a fixed portion 301 and a pair of mounting portions (first mounting portion, second mounting portion) 305, 306. The fixed portion 301 is mounted on a device frame (not shown). The pair of mounting portions 305, 306 are mounted on rails provided on the fixed portion 301, and are independently movable in the Y direction.

The moving mechanism 400 has a fixed part 401 and a pair of mounting parts (first mounting part, second mounting part) 405, 406. The fixed part 401 is mounted on a device frame (not shown). The pair of mounting parts 405, 406 are respectively mounted on rails provided on the fixed part 401, and are independently movable along the X direction. Furthermore, the rails of the fixed part 401 are arranged to intersect with the rails of the fixed part 301 in a three-dimensional manner.

The laser processing head 10A is mounted on the mounting portion 305 of the moving mechanism 300. The laser processing head 10A irradiates the object 100 supported by the support portion 7 with laser light in a state where the laser processing head 10A is opposite to the support portion 7 in the Z direction. The laser light emitted from the laser processing head 10A is guided from the light source unit (not shown) by the optical fiber 2. The laser processing head 10B is mounted on the mounting portion 306 of the moving mechanism 300. The laser processing head 10B irradiates the object 100 supported by the support portion 7 with laser light in a state where the laser processing head 10B is opposite to the support portion 7 in the Z direction. The laser light emitted from the laser processing head 10B is guided from the light source unit (not shown) by the optical fiber 2.

The laser processing head 10C is mounted on the mounting portion 405 of the moving mechanism 400. The laser processing head 10C irradiates the object 100 supported by the support portion 7 with laser light in a state where the laser processing head 10C is opposite to the support portion 7 in the Z direction. The laser light emitted from the laser processing head 10C is guided from the light source unit (not shown) by the optical fiber 2. The laser processing head 10D is mounted on the mounting portion 406 of the moving mechanism 400. The laser processing head 10D irradiates the object 100 supported by the support portion 7 with laser light in a state where the laser processing head 10D is opposite to the support portion 7 in the Z direction. The laser light emitted from the laser processing head 10D is guided from the light source unit (not shown) by the optical fiber 2.

The structure of the pair of laser processing heads 10A and 10B of the laser processing device 1 shown in Fig. 8 is the same as the structure of the pair of laser processing heads 10A and 10B of the laser processing device 1 shown in Fig. 1. The structure of the pair of laser processing heads 10C and 10D of the laser processing device 1 shown in Fig. 8 is the same as the structure of the pair of laser processing heads 10A and 10B of the laser processing device 1 shown in Fig. 1 rotated 90 degrees with the axis parallel to the Z direction as the center line.

For example, the frame (first frame) 11 of the laser machining head 10C is mounted on the mounting portion 65 in such a manner that the fourth wall portion 24 is located on the laser machining head 10D side relative to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25. In addition, the focusing portion 14 of the laser machining head 10C is offset in the Y direction toward the fourth wall portion 24 side (that is, the laser machining head 10D side).

The frame (second frame) 11 of the laser machining head 10D is mounted on the mounting portion 66 in such a manner that the fourth wall portion 24 is located on the laser machining head 10C side relative to the third wall portion 23, and the sixth wall portion 26 is located on the support portion 7 side relative to the fifth wall portion 25. In addition, the focusing portion 14 of the laser machining head 10D is offset toward the fourth wall portion 24 side (that is, the laser machining head 10C side) in the Y direction.

As described above, in the laser processing device 1 shown in FIG8 , when the pair of laser processing heads 10A and 10B are moved in the Y direction, the focusing portion 14 of the laser processing head 10A and the focusing portion 14 of the laser processing head 10B can be brought close to each other. Also, when the pair of laser processing heads 10C and 10D are moved in the X direction, the focusing portion 14 of the laser processing head 10C and the focusing portion 14 of the laser processing head 10D can be brought close to each other.

Furthermore, the laser processing head and the laser processing device are not limited to those that form the modified region inside the object 100, and may also be those that perform other laser processing.

Next, each embodiment is described. In the following description, descriptions that are repeated with the above-mentioned embodiments are omitted.

[First embodiment] As shown in FIG. 9, the laser processing device 101 of the first embodiment forms a modified area on the object 100 by irradiating the first laser light L1 toward the object 100 in accordance with the focal point (at least a part of the focal area). The laser processing device 101 performs finishing processing on the object 100 to obtain (manufacture) a semiconductor device. The laser processing device 101 forms the modified area along a line M3 extending in a ring shape inside the outer edge of the object 100. The laser processing device 101 has a mounting table 107, a first laser processing head 10A, a first Z-axis track 106A, an X-axis track 108, an alignment camera 110, and a control unit 9.

The trimming process is a process for removing unnecessary parts from the object 100. The trimming process includes a laser processing method for forming a modified area 4 on the object 100 by irradiating the first laser light L1 toward the object 100 in accordance with the focal point (at least a part of the focal area). The object 100 includes, for example, a semiconductor wafer formed in the shape of a circular plate. The object is not particularly limited and can be formed of various materials and can also present various shapes. A functional element (not shown) is formed on the surface 100a of the object 100. The functional element is, for example, a light-receiving element such as a light-emitting diode, a light-emitting element such as a laser diode, a circuit element such as a memory, etc. Furthermore, in the following description, the X direction corresponds to the Y direction of the aforementioned laser processing device 1 (refer to Figure 1), and the Y direction corresponds to the X direction of the aforementioned laser processing device 1 (refer to Figure 1).

As shown in FIG. 10( a) and FIG. 10( b), an effective area R and a removal area E are set in the object 100. The effective area R is a portion corresponding to the semiconductor device to be obtained. The effective area R here is a disk-shaped portion including the central portion when the object 100 is viewed from the thickness direction. The removal area E is an area further outside the effective area R of the object 100. The removal area E is an outer edge portion outside the effective area R in the object 100. The removal area E here is a ring-shaped portion included in the effective area R. The removal area E includes the peripheral portion (the bevel portion of the outer edge) when the object 100 is viewed from the thickness direction. The setting of the effective area R and the removal area E can be performed in the control unit 9. The effective area R and the removal area E can also be specified by coordinates.

The mounting table 107 is a support portion for mounting the object 100. The mounting table 107 is constructed in the same manner as the aforementioned support portion 7 (see FIG. 1 ). In the mounting table 107 of the present embodiment, the object 100 is mounted with the back surface 100b of the object 100 being set as the laser light incident side, i.e., the upper side (the surface 100a being set as the mounting table 107 side, i.e., the lower side). The mounting table 107 has a rotation axis C disposed at the center thereof. The rotation axis C is an axis extending along the Z direction. The mounting table 107 can rotate around the rotation axis C. The mounting table 107 is rotationally driven by the driving force of a conventional driving device such as a motor.

The first laser processing head 10A irradiates the object 100 placed on the mounting table 107 with the first laser light L1 along the Z direction to form a modified area inside the object 100. The first laser processing head 10A is mounted on the first Z-axis track 106A and the X-axis track 108. The first laser processing head 10A can be moved linearly in the Z direction along the first Z-axis track 106A by the driving force of a known driving device such as a motor. The first laser processing head 10A can be moved linearly in the X direction along the X-axis track 108 by the driving force of a known driving device such as a motor. The first laser processing head 10A constitutes an irradiation unit.

As described above, the first laser processing head 10A has a reflective spatial light modulator 34. The reflective spatial light modulator 34 is a shaping unit that shapes the shape of the focal point in a plane perpendicular to the optical axis of the first laser light L1 (hereinafter also referred to as "beam shape"). The reflective spatial light modulator 34 shapes the first laser light L1 in such a way that the beam shape has a longitudinal direction. For example, the reflective spatial light modulator 34 shapes the beam shape into an ellipse by displaying a modulation pattern that makes the beam shape into an ellipse on the liquid crystal layer.

The shape of the light beam is not limited to an ellipse, and may be a long strip shape. The shape of the light beam may also be a flat circle, an oblong circle, or a racetrack shape. The shape of the light beam may also be a long triangle, rectangle, or polygon. The modulation pattern of the reflective spatial light modulator 34 that achieves such a beam shape may also include at least one of a slit pattern and a non-point pattern. Furthermore, in the case where the first laser light L1 has a plurality of focal points due to astigmatism, etc., the shape of the focal point on the most upstream side of the optical path of the first laser light L1 among the plurality of focal points is the beam shape of this embodiment (the same is true for other laser lights). The length direction here is the long axis direction of the ellipse of the beam shape, also referred to as the long axis direction of the ellipse.

The beam shape is not limited to the shape of the focal point, and may be a shape near the focal point, that is, a shape of a part of the focal area (area where light is focused). For example, in the case of the first laser light L1 with astigmatism, as shown in FIG. 71(a), in the area on the side of the laser light incident surface near the focal point, the beam shape 71 has a longitudinal direction NH. The beam intensity distribution in the plane of the beam shape 71 in FIG. 71(a) (in the plane of the Z-direction position on the side of the laser light incident surface near the focal point) is formed to have a distribution with a stronger intensity in the longitudinal direction NH, and the direction in which the beam intensity is stronger is consistent with the longitudinal direction NH.

In the case of the first laser light L1 with astigmatism, as shown in FIG71(c), in the area on the opposite side of the laser light incident surface near the focal point, the beam shape 71 has a length direction NH0 that is perpendicular to the length direction NH of the area on the laser light incident surface side (refer to FIG71(a)). The beam intensity distribution in the plane of the beam shape 71 in FIG71(c) (in the plane of the Z direction position on the opposite side of the laser light incident surface near the focal point) is formed to have a distribution with a stronger intensity in the length direction NH0, and the direction in which the beam intensity is stronger is consistent with the length direction NH0. In the case of the first laser light L1 with astigmatism, as shown in FIG. 71( b ), in the region between the laser light incident surface side near the focal point and the opposite surface side, the beam shape 71 does not have a longitudinal direction but becomes a circle.

In the case of the first laser light L1 having such astigmatism, the present embodiment takes the present embodiment as a part of the focusing area as the object, which is the area on the side where the laser light enters the surface near the focal point. The beam shape of the present embodiment as the object is the beam shape 71 as shown in FIG. 71(a).

Furthermore, by adjusting the modulation pattern of the reflective spatial light modulator 34, the position of the focusing area to form the beam shape 71 as shown in FIG. 71(a) can be controlled to a desired position. For example, the area on the opposite side of the laser light incident surface near the focal point can be controlled to have the beam shape 71 as shown in FIG. 71(a). Also, for example, the area between the laser light incident surface side and the opposite side thereof near the focal point can be controlled to have the beam shape 71 as shown in FIG. 71(a). The position of a part of the focusing area is not particularly limited, and any position between the laser light incident surface and the opposite side of the object 100 can be used.

For example, in the case of using a slit or elliptical optical system controlled by a modulation pattern and/or a mechanical mechanism, as shown in FIG72(a), in the area on the laser light incident surface near the focal point, the beam shape 71 has a longitudinal direction NH. The beam intensity distribution in the plane of the beam shape 71 in FIG72(a) (in the plane of the Z-direction position on the laser light incident surface near the focal point) is formed to have a distribution with a stronger intensity in the longitudinal direction NH, and the direction of the stronger beam intensity is consistent with the longitudinal direction NH.

In the case of using a slit or elliptical optical system, as shown in FIG72(c), in the area on the opposite side of the laser light incident surface near the focal point, the beam shape 71 has the same length direction NH as the length direction NH of the area on the laser light incident surface side (refer to FIG71(a)). The beam intensity distribution in the plane of the beam shape 71 in FIG72(c) (in the plane of the Z direction position on the opposite side of the laser light incident surface near the focal point) is formed to have a distribution with a stronger intensity in the length direction NH, and the direction of the stronger beam intensity is consistent with the length direction NH. In the case of using a slit or elliptical optical system, as shown in FIG72(b), at the focal point, the beam shape 71 has a longitudinal direction NH0 that is perpendicular to the longitudinal direction NH of the area on the laser light incident side (see FIG72(a)). The beam intensity distribution in the plane of the beam shape 71 in FIG72(b) (in the plane of the Z direction position of the focal point) is formed to have a distribution with a stronger intensity in the longitudinal direction NH0, and the direction of the stronger beam intensity is consistent with the longitudinal direction NH0.

When such a slit or elliptical optical system is used, the beam shape 71 outside the focal point becomes a shape having a longitudinal direction, and the beam shape 71 outside the focal point is the beam shape targeted by this embodiment. That is, a part of the focal area targeted by this embodiment includes the area on the side of the laser light incident surface near the focal point, and the beam shape targeted by this embodiment is the beam shape 71 shown in FIG. 72(a).

The first laser processing head 10A is provided with a distance measuring sensor 36. The distance measuring sensor 36 emits a distance measuring laser light to the laser light incident surface of the object 100, and detects the distance measuring light reflected by the laser light incident surface, thereby obtaining displacement data of the laser light incident surface of the object 100. Furthermore, when the distance measuring sensor 36 is a sensor that is not coaxial with the first laser light L1, a sensor of a triangular distance measuring method, a laser confocal point method, a white confocal point method, a spectral interference method, an astigmatism method, etc. can be used. Furthermore, when the distance measuring sensor 36 is a sensor that is coaxial with the first laser light L1, a sensor of an astigmatism method, etc. can be used. The circuit section 19 (see FIG. 3 ) of the first laser processing head 10A drives the driving section 18 (see FIG. 5 ) based on the displacement data obtained from the distance measuring sensor 36, so that the focusing section 14 follows the laser light incident surface. In this way, the focusing section 14 is moved along the Z direction based on the displacement data, and the distance between the laser light incident surface of the object 100 and the focusing point of the first laser light L1, i.e., the first focusing point, is maintained constant. Such a distance measuring sensor 36 and its control (hereinafter also referred to as "following control") are the same in other laser processing heads.

The first Z-axis track 106A is a track extending along the Z direction. The first Z-axis track 106A is mounted on the first laser processing head 10A via the mounting portion 65. The first Z-axis track 106A is a track for the first laser processing head 10A to move along the Z direction, so that the first focal point of the first laser light L1 moves along the Z direction. The first Z-axis track 106A corresponds to the track of the aforementioned moving mechanism 6 (refer to FIG. 1 ) or the aforementioned moving mechanism 300 (refer to FIG. 8 ). The first Z-axis track 106A constitutes a vertical moving mechanism.

The X-axis track 108 is a track extending along the X direction. The X-axis track 108 is mounted on the first and second Z-axis tracks 106A and 106B, respectively. The X-axis track 108 moves the first laser processing head 10A along the X direction, so that the first focal point of the first laser light L1 moves along the X direction. The X-axis track 108 moves the first laser processing head 10A so that the first focal point passes through the rotation axis C or its vicinity. The X-axis track 108 is a track corresponding to the aforementioned moving mechanism 6 (refer to FIG. 1 ) or the aforementioned moving mechanism 300 (refer to FIG. 8 ). The X-axis track 108 constitutes a horizontal moving mechanism.

The alignment camera 110 is a camera for obtaining images used for various adjustments. The alignment camera 110 takes an image of the object 100. The alignment camera 110 is provided in the mounting portion 65 where the first laser processing head 10A is mounted, and can move synchronously with the first laser processing head 10A.

The control unit 9 is constituted as a computer device including a processor, a memory, a storage, and a communication device. In the control unit 9, the software (program) loaded on the memory, etc. is executed by the processor, and the reading and writing of data in the memory and the storage and the communication through the communication device are controlled by the processor. In this way, the control unit 9 can achieve various functions.

The control unit 9 controls the stage 107 and the first laser processing head 10A. The control unit 9 controls the rotation of the stage 107, the irradiation of the first laser light L1 from the first laser processing head 10A, the beam shape, and the movement of the first focal point. The control unit 9 can perform various controls based on the rotation information about the rotation amount of the stage 107 (hereinafter also referred to as "θ information"). The θ information can be obtained from the driving amount of the driving device that rotates the stage 107, and can also be obtained by other sensors. The θ information can be obtained by various known methods. The θ information here includes the rotation angle based on the state when the object 100 is located at the 0° direction.

The control unit 9 rotates the mounting table 107 while positioning the first focal point along the line M3 (the periphery of the effective area R) of the object 100, controls the start and stop of irradiation of the first laser light L1 of the first laser processing head 10A according to the θ information, and performs peripheral processing to form a modified area along the periphery of the effective area R.

The control unit 9 performs a removal process for forming a modified region in the removal region E by irradiating the removal region E with the first laser light L1 and moving the first focal point of the first laser light L1 without rotating the stage 107 .

The control unit 9 controls at least one of the rotation of the mounting table 107, the irradiation of the first laser light L1 from the first laser processing head 10A, and the movement of the first focal point, so that the distance between the multiple modified points contained in the modified area (the distance between the modified points adjacent to the processing direction) becomes constant.

The control unit 9 obtains the reference position (position in the 0° direction) of the rotation direction of the object 100 and the diameter of the object 100 from the image captured by the alignment camera 110. The control unit 9 controls the movement of the first laser processing head 10A so that the first laser processing head 10A can move along the X-axis track 108 until it reaches the rotation axis C of the mounting table 107.

Next, an example of a method for performing trimming processing on the object 100 using the laser processing device 101 to obtain (manufacture) a semiconductor device will be described below.

First, the object 100 is placed on the mounting table 107 with the back surface 100b being the laser light incident side. The surface 100a of the object 100 on which the functional element is mounted is adhered to a supporting substrate or a tape member for protection.

Next, the trimming process is performed. In the trimming process, the peripheral processing is performed by the control unit 9. Specifically, as shown in FIG11(a), while the stage 107 is rotated at a certain rotation speed, the first focal point (focal point) P1 is located at the position of the object 100 along the periphery of the effective area R, and the irradiation start and stop of the first laser light L1 of the first laser processing head 10A are controlled according to the θ information. Thereby, as shown in FIG11(b) and FIG11(c), a modified area 4 is formed along the line M3 (the periphery of the effective area R). The formed modified area 4 includes a modified point and a crack extending from the modified point.

In the trimming process, the control unit 9 performs the removal process. Specifically, as shown in FIG. 12( a), the first laser light L1 is irradiated to the removal area E without rotating the stage 107, and the first laser processing head 10A is moved in the direction of separation from each other along the X-axis track 108, so that the first focal point P1 of the first laser light L1 moves in the direction of separation from the center of the object 100. After the stage 107 is rotated 90°, the first laser light L1 is irradiated to the removal area E, and the first laser processing head 10A is moved in the direction of separation from each other along the X-axis track 108, so that the first focal point P1 of the first laser light L1 moves in the direction of separation from the center of the object 100.

Thus, as shown in FIG. 12( b ), a modified region 4 is formed along a line extending in a manner that divides the removal region E into four equal parts when viewed from the Z direction. The formed modified region 4 includes a modified point and a crack extending from the modified point. The crack may reach at least one of the surface 100a and the back surface 100b, or may not reach at least one of the surface 100a and the back surface 100b. Then, as shown in FIG. 13( a ) and FIG. 13( b ), the removal region E is removed, for example, by a jig or air, with the modified region 4 as a boundary.

Next, as shown in FIG. 13( c ), the peeled surface 100h of the object 100 is finely ground or polished with a grinding material KM such as a grindstone. In the case where the object 100 is peeled off by etching, the polishing can also be simplified. As a result of the above, a semiconductor device 100K is obtained.

Next, the finishing process of this embodiment will be described in more detail.

As shown in FIG14 , the object 100 is in the shape of a plate, and has a surface 100a and a back surface 100b as its main surface (refer to FIG10 ). The object 100 is a wafer having the (100) surface as the main surface. The object 100 is a silicon wafer formed of silicon. The object 100 has: a first crystal orientation K1 perpendicular to the (110) surface on one side; and a second crystal orientation K2 perpendicular to the (110) surface on the other side. The (110) surface is a cleavage plane. The first crystal orientation K1 and the second crystal orientation K2 are cleavage directions, that is, directions in which turtle cracks are most likely to extend in the object 100. The first crystal orientation K1 and the second crystal orientation K2 are orthogonal to each other.

An alignment object 100n is provided on the object 100. For example, the alignment object 100n is a position in the 0° direction of the object 100, and has a certain relationship in the θ direction (the rotation direction around the rotation axis C of the mounting table 107). The position in the 0° direction refers to the position of the object 100 that serves as a reference in the θ direction. For example, the alignment object 100n is a cut formed on the outer edge. Furthermore, the alignment object 100n is not particularly limited, and may be an orientation plane of the object 100, or may be a pattern of a functional element. In the illustrated example, the alignment object 100n is provided at a position in the 0° direction of the object 100. In other words, the alignment object 100n is provided at a position on a diameter of the object 100 extending in the direction of the second crystal orientation K2.

In the object 100, a line M3 is set as a predetermined trimming line. The line M3 is a line for forming a predetermined modified area 4. The line M3 extends in a ring shape inside the outer edge of the object 100. The line M3 here extends in a circular ring shape. The line M3 is set at the boundary between the effective area R and the removal area E of the object 100. The setting of the line M3 can be performed in the control unit 9. The line M3 is a virtual line, but it can also be a line actually drawn. The line M3 can also be specified by coordinates.

As shown in FIG9 , the control unit 9 of the laser processing device 101 includes an acquisition unit 9a, a determination unit 9b, a processing control unit 9c, and an adjustment unit 9d. The acquisition unit 9a acquires object information about the object 100. The object information includes, for example, information about the crystal orientation (the first crystal orientation K1 and the second crystal orientation K2) of the object 100; and alignment information about the position of the object 100 in the 0° direction and the diameter of the object 100. The acquisition unit 9a can acquire the object information based on the image captured by the alignment camera 110 and inputs such as user operation or external communication.

The acquisition unit 9a acquires line information about the line M3. The line information includes information about the line M3 and information about the moving direction (also referred to as "processing direction") of the first focal point P1 when the first focal point P1 is relatively moved along the line M3. For example, the processing direction is the connecting direction of the line M3 passing through the first focal point P1 located on the line M3. The acquisition unit 9a acquires the line information based on input such as user operation or external communication.

The determining unit 9b determines the orientation in the length direction of the case where the first light-converging point P1 is relatively moved along the line M3 based on the object information and line information acquired by the acquiring unit 9a, so that the length direction of the light beam shape intersects with the processing direction. Specifically, the determining unit 9b determines the orientation of the length direction NH into a first orientation and a second orientation based on the object information and line information. The first orientation is the orientation in the length direction of the light beam shape when the first light-converging point P1 is relatively moved along the first area M31 of the line M3. The second orientation is the orientation in the length direction of the light beam shape when the first light-converging point P1 is relatively moved along the second area M32 of the line M3. Hereinafter, the "orientation in the length direction of the light beam shape" will be referred to simply as the "orientation of the light beam shape."

The first region M31 is a case where a point at which the line M3 is orthogonal to the second crystal orientation K2 of the object 100 is taken as the 0° point, and includes the portion from the 0° point to the 45° point, the portion from the 90° point to the 135° point, the portion from the 180° point to the 225° point, and the portion from the 270° point to the 315° point. The second region M32 includes a portion from a point at 45° to a point at 90°, a portion from a point at 135° to a point at 180°, a portion from a point at 225° to a point at 270°, and a portion from a point at 315° to a point at 360°, when the line M3 and the second crystal orientation K2 of the object 100 are perpendicular to each other at 0°. In the following description, the definition of the angle of each point on the line M3 is the same.

The first area M31 is a case where the first focal point P1 is relatively moved along the line M3, and includes an area where the processing angle described later is 0° to less than 45°, or -90° to less than -45°. The second area M32 is a case where the first focal point P1 is relatively moved along the line M3, and includes an area where the processing angle described later is 45° to less than 90°, or -45° to less than 0°. Incidentally, the first area M31 and the second area M32 of the line M3 correspond to the first part of the fourth embodiment described later.

As shown in FIG. 15( b ), the processing angle α is the angle of the processing direction BD to the first crystal orientation K1. When viewed from the back surface 100 b as the laser light incident surface, the angle in the counterclockwise direction is set as a positive (+) angle, and the angle in the clockwise direction is set as a negative (-) angle. The processing angle α can be obtained based on the θ information, object information, and line information of the mounting table 107. When the first focal point P1 is relatively moved along the first area M31, it can be regarded as a case where the processing angle α is greater than 0° and less than 45°, or greater than -90° and less than -45°. When the first focal point P1 is relatively moved along the second area M32, the processing angle α can be regarded as being greater than 45° and less than 90°, or greater than -45° and less than 0°.

The first orientation and the second orientation are orientations inclined with respect to the processing direction BD in such a manner that the first crystal orientation K1 and the second crystal orientation K2, whichever has a larger angle with respect to the processing direction BD (the one farther away), approaches the first crystal orientation K1 and the second crystal orientation K2.

The first orientation and the second orientation are as follows when the processing angle α is greater than 0° and less than 90°. The first orientation is an orientation in a direction in which the length direction NH is inclined to the processing direction BD, toward the side close to the second crystal orientation K2. The second orientation is an orientation in a direction in which the length direction NH is inclined to the processing direction BD, toward the side close to the first crystal orientation K1. The first orientation is an orientation in a direction in which the length direction NH is inclined to the processing direction BD by 10° to 35° toward the side close to the second crystal orientation K2 from the processing direction BD. The second orientation is an orientation in a direction in which the length direction NH is inclined to the processing direction BD by 10° to 35°.

The first orientation is the orientation of the beam shape 71 when the beam angle β is +10° to +35°. The second orientation is the orientation of the beam shape 71 when the beam angle β is -35° to -10°. The beam angle β is the angle between the processing direction BD and the longitudinal direction NH. The beam angle β is the angle in the counterclockwise direction as a positive (+) angle and the angle in the clockwise direction as a negative (-) angle when viewed from the back surface 100b as the laser light incident surface. The beam angle β can be obtained according to the orientation of the beam shape 71 and the processing direction BD.

The processing control unit 9c controls the start and stop of the laser processing of the object 100. The processing control unit 9c performs a first process, which is to relatively move the first focal point P1 along the first area M31 of the line M3 to form the modified area 4, and to stop the formation of the modified area 4 in the area other than the first area M31 of the line M3. The processing control unit 9c performs a second process, which is to relatively move the first focal point P1 along the second area M32 of the line M3 to form the modified area 4, and to stop the formation of the modified area 4 in the area other than the second area M32 of the line M3.

The switching of the formation and stop of the modified region 4 by the processing control unit 9c can be achieved in the following manner. For example, in the first laser processing head 10A, by switching the start and stop (ON/OFF) of the irradiation (output) of the first laser light L1, the formation of the modified region 4 and the stop of the formation can be switched. Specifically, in the case where the laser oscillator is composed of a solid laser, by switching the ON/OFF of a Q switch (AOM (acoustic optical modulator), EOM (electro-optical modulator) etc.) provided in the resonator, the start and stop of the irradiation of the first laser light L1 can be switched at a high speed. When the laser oscillator is composed of an optical fiber laser, the output of the semiconductor laser constituting the amplifier (excitation) laser is switched on/off to switch the start and stop of the irradiation of the first laser light L1 at high speed. When the laser oscillator uses an external modulation element, the irradiation of the first laser light L1 is switched on/off at high speed by switching on/off the external modulation element (AOM, EOM, etc.) provided outside the resonator.

Alternatively, the switching of the formation and the stopping of the modified area 4 by the process control unit 9c can also be achieved in the following manner. For example, the formation of the modified area 4 and the stopping of the formation can be switched by controlling a mechanical mechanism such as a shutter to open and close the optical path of the first laser light L1. The formation of the modified area 4 can also be stopped by switching the first laser light L1 to CW light (continuous wave). The formation of the modified area 4 can also be stopped by displaying a pattern that is made to be in a state that cannot modify the focusing state of the first laser light L1 (for example, a satin pattern that scatters laser light) on the liquid crystal layer of the reflective spatial light modulator 34. The formation of the modified area 4 can also be stopped by controlling an output adjustment unit such as an attenuator to reduce the output of the first laser light L1 to a state where the modified area cannot be formed. The formation of the modified region 4 may be stopped by switching the polarization direction. The formation of the modified region 4 may be stopped by scattering (scattering) the first laser light L1 in directions other than the optical axis to cut it off.

The adjusting unit 9d adjusts the orientation of the beam shape 71 by controlling the reflective spatial light modulator 34. When the process control unit 9c performs the first process, the adjusting unit 9d adjusts the orientation of the beam shape 71 to form the first orientation. When the process control unit 9c performs the second process, the adjusting unit 9d adjusts the orientation of the beam shape 71 to form the second orientation. The adjusting unit 9d adjusts the longitudinal direction NH of the beam shape 71 so that the longitudinal direction NH of the beam shape 71 changes within the range of ±35° with respect to the process travel direction BD.

In the laser processing apparatus 101, the trimming process (laser processing method) described below is performed.

In the trimming process, first, the mounting table 107 is rotated so that the alignment camera 110 is located directly above the alignment target 100n of the object 100 and the focus of the alignment camera 110 is focused on the alignment target 100n, and the first laser processing head 10A equipped with the alignment camera 110 is moved along the X-axis track 108 and the first Z-axis track 106A.

The image is taken by the alignment camera 110. The position of the object 100 in the 0° direction is acquired based on the image captured by the alignment camera 110. The acquisition unit 9a acquires object information and line information (information acquisition process) based on the image captured by the alignment camera 110 and inputs such as user operation or external communication. The object information includes alignment information about the position and diameter of the object 100 in the 0° direction. As described above, since the position of the alignment object 100n in the 0° direction has a certain relationship in the θ direction, the position of the alignment object 100n in the 0° direction can be acquired by acquiring the position of the alignment object 100n from the captured image. The diameter of the object 100 is acquired based on the image captured by the alignment camera 110. Furthermore, the diameter of the object 100 may also be set by input from the user.

Based on the acquired object information and line information, the determining unit 9b determines the first orientation and the second orientation as the orientation in the longitudinal direction NH of the beam shape 71 when the first focal point P1 is relatively moved along the line M3 (determination process).

Next, the stage 107 is rotated so that the object 100 is located at the 0° direction. In the X direction, the first laser processing head 10A is moved along the X-axis track 108 and the first Z-axis track 106A so that the first focal point P1 is located at the predetermined trimming position. For example, the predetermined trimming position is a predetermined position on the line M3 of the object 100.

Then, the stage 107 is made to rotate. The tracking by the back side 100b of the distance measuring sensor is started. Furthermore, before the tracking by the distance measuring sensor is started, it is confirmed in advance that the position of the first focal point P1 is within the measurable range of the distance measuring sensor. When the rotation speed of the stage 107 becomes constant (constant speed), the irradiation of the first laser light L1 by the first laser processing head 10A is started.

By rotating the stage 107 and switching the irradiation of the first laser light L1 by the process control unit 9c on/off, as shown in FIG. 15(a), the first focal point P1 is relatively moved along the first area M31 on the line M3 to form the modified area 4, and the formation of the modified area 4 in the area other than the first area M31 on the line M3 is stopped (first process). As shown in FIG. 15(b), when the first process is executed, the orientation of the beam shape 71 is adjusted by the adjustment unit 9d to form the first orientation. That is, the orientation of the beam shape 71 in the first process is fixed at the first orientation.

Then, by rotating the stage 107 and switching the irradiation of the first laser light L1 by the process control unit 9c on/off, as shown in FIG. 16(a), the first focal point P1 is relatively moved along the second area M32 on the line M3 to form the modified area 4, and the formation of the modified area 4 in the area other than the first area M31 on the line M3 is stopped (second process). As shown in FIG. 16(b), when executing the second process, the orientation of the beam shape 71 is adjusted by the adjustment unit 9d to form the second orientation. That is, the orientation of the beam shape 71 in the second process is fixed at the second orientation.

The Z-direction position of the predetermined trimming position is changed, and the first processing step and the second processing step are repeated. In the above manner, a plurality of rows of modified regions 4 are formed in the Z-direction along the line M3 of the periphery of the effective region R inside the object 100.

As described above, in the laser processing device 101 of the present embodiment, the first processing is performed, and the first processing is to relatively move the first focal point P1 along the first area M31 of the line M3 to form the modified area 4, and to stop the formation of the modified area 4 in the area other than the first area M31 of the line M3. In the first processing, the orientation of the longitudinal direction NH of the beam shape 71 is adjusted to an orientation intersecting with the processing travel direction BD, that is, the first orientation determined based on the object information and the line information. In addition, the second processing is performed, and the second processing is to relatively move the first focal point P1 along the second area M32 of the line M3 to form the modified area 4, and to stop the formation of the modified area 4 in the area other than the second area M32 of the line M3. In the second processing, the orientation of the longitudinal direction NH of the beam shape 71 is adjusted to an orientation intersecting with the processing direction BD, that is, a second orientation determined based on the object information and the line information. Therefore, only when the longitudinal direction NH is consistent with the processing direction BD, the first focal point P1 is relatively moved along the line M3, so that even if the quality of the trimmed surface of the first area M31 and the second area M32 is reduced due to the physical properties of the object 100, the reduction in the quality of the trimmed surface can be suppressed. Therefore, in the laser processing device 101, it is possible to suppress the situation in which the quality of the trimmed surface of the object 100 from which the outer edge portion, that is, the area E, is removed is reduced depending on the location.

In the laser processing method using the laser processing device 101 of the present embodiment, a first processing process is implemented, wherein the first focal point P1 is relatively moved along the first area M31 of the line M3 to form a modified area 4, and the formation of the modified area 4 in the area outside the first area M31 of the line M3 is stopped. In the first processing process, the orientation of the longitudinal direction NH is adjusted to an orientation intersecting with the processing travel direction BD, that is, a first orientation determined based on object information and line information. In addition, a second processing process is implemented, wherein the first focal point P1 is relatively moved along the second area M32 of the line M3 to form a modified area 4, and the formation of the modified area 4 in the area outside the second area M32 of the line M3 is stopped. In the second processing step, the orientation of the longitudinal direction NH is adjusted to an orientation intersecting with the processing direction BD, that is, the second orientation determined based on the object information and the line information. Therefore, only when the longitudinal direction NH of the beam shape 71 is consistent with the processing direction BD, the first focal point P1 is relatively moved along the line M3, so that even if the quality of the trimmed surface of the first area M31 and the second area M32 is reduced due to the physical properties of the object 100, the quality reduction of the trimmed surface can be suppressed. Therefore, in the laser processing method using the laser processing device 101, it is possible to suppress the situation in which the quality of the trimmed surface of the object 100 from which the outer edge portion, that is, the area E, is removed is reduced depending on the location.

In particular, in the present embodiment, the orientation of the beam shape 71 is fixed at the first orientation in the first process (first processing step), and similarly, the orientation of the beam shape 71 is fixed at the second orientation in the second process (second processing step). In the first process and the second process (first processing step and second processing step), the beam shape 71 does not change but is formed to be constant, so that stable laser processing can be achieved.

Furthermore, depending on the location where the modified region 4 is formed, there is a risk that the tortoise crack extending from the modified region 4 is affected by the crystal orientation that is easily cleaved, and becomes difficult to extend in the processing direction BD or the quality of the trimmed surface may deteriorate. In this regard, in the laser processing device 101, the object information includes information about the crystal orientation (the first crystal orientation K1 and the second crystal orientation K2) of the object 100. The line information includes information about the processing direction BD. Thereby, even if the object 100 has a crystal orientation, it is possible to suppress the quality of the trimmed surface of the object 100 from being reduced depending on the location.

The laser processing device 101 of the present embodiment includes the reflective spatial light modulator 34 as a shaping unit, and the adjusting unit 9d adjusts the orientation in the longitudinal direction NH by controlling the reflective spatial light modulator 34. Thus, the orientation in the longitudinal direction NH can be adjusted reliably.

In the laser processing device 101 of the present embodiment, the object 100 is a wafer having a (100) plane as a main surface, a first crystal orientation K1 perpendicular to the (110) plane on one side, and a second crystal orientation K2 perpendicular to the (110) plane on the other side. The line M3 extends in a circular ring shape when viewed from a direction perpendicular to the main surface of the object 100. The first area M31 is a region where the processing angle α is greater than 0° and less than 45° when the first focal point P1 is relatively moved along the line M3. The second area M32 is a region where the processing angle α is greater than 45° and less than 90° when the first focal point P1 is relatively moved along the line M3. Thus, even when the object 100 is a wafer having a (100) plane as a main surface, it is possible to suppress the quality of the trimmed surface of the object 100 from being degraded depending on the location.

In the laser processing device 101 of the present embodiment, the first orientation and the second orientation are orientations in a direction inclined with respect to the processing direction BD in such a manner that the first crystal orientation K1 and the second crystal orientation K2 are close to the one with a larger angle with respect to the processing direction BD. Thus, even when the object 100 is a wafer with a (100) plane as a main surface, it is possible to more reliably suppress the degradation of the quality of the trimmed surface of the object 100 in the first region M31 and the second region M32.

For example, in the case of pulling the tortoise crack in the first crystal orientation K1, since the orientation of the beam shape 71 is made the orientation of the processing direction BD, the second crystal orientation K2 is tilted to the processing direction BD, which is opposite to the first crystal orientation K1. As shown in FIG. 15(b), the tortoise crack extension force W1 by the crystal orientation (crystal axis) is offset by the tortoise crack extension force W2 by making the beam shape 71 into a long strip, so that the tortoise crack can be extended along the processing direction BD with good accuracy.

For example, in the case of pulling the tortoise crack in the second crystal orientation K2, since the orientation of the beam shape 71 is made the orientation of the processing direction BD, the first crystal orientation K1 is tilted to the opposite side of the processing direction BD close to the second crystal orientation K2. As shown in FIG. 16(b), the tortoise crack extension force W1 due to the crystal orientation is offset by the tortoise crack extension force W2 due to making the beam shape 71 into a long strip, so that the tortoise crack can be extended along the processing direction BD with good accuracy.

In the laser processing device 101 of the present embodiment, the first orientation is an orientation in a direction inclined by 10° to 35° from the processing direction BD, on the side close to the first crystal orientation K1 and the second crystal orientation K2, which have a larger angle with the processing direction BD. The second orientation is an orientation in a direction inclined by 10° to 35° from the processing direction BD, on the side close to the first crystal orientation K1 and the second crystal orientation K2, which have a larger angle with the processing direction BD. Thus, even when the object 100 is a wafer having a (100) plane as a main surface, it is possible to more reliably suppress the degradation of the quality of the trimmed surface of the object 100 in the first region M31 and the second region M32.

The laser processing device 101 of the present embodiment and the laser processing method using the laser processing device 101 relatively move the first focal point P1 along the line M3 in a state where the longitudinal direction NH of the beam shape 71 intersects with the processing direction BD in the first part (the first area M31 or the second area M32) of the line M3. Thus, for example, only in a state where the longitudinal direction NH and the processing direction BD coincide with each other, the first focal point P1 is relatively moved along the line M3, so that even if the quality of the trimmed surface of the first part of the line M3 is degraded due to the physical properties of the object 100, the deterioration of the quality of the trimmed surface can be suppressed. It is possible to reduce the deterioration of the quality of the trimmed surface depending on the part.

FIG17 is a time chart showing a specific first operation example in which laser processing is performed by the laser processing device 101 of FIG9. The tracking processing in FIG17 refers to the process of emitting distance measuring laser light to the laser light incident surface of the object 100 by the distance measuring sensor 36, and then detecting the distance measuring light reflected by the laser light incident surface to obtain the displacement data of the laser light incident surface. The tracking control in FIG17 is the aforementioned control by the distance measuring sensor 36. The recording of the tracking control refers to the control of obtaining the displacement data, and the reproduction of the tracking control refers to the control of driving the driving unit 18 (refer to FIG5) based on the displacement data so that the focusing unit 14 follows the laser light incident surface. The "processing position in the Z direction" refers to the focusing position (focal point) of the focusing unit 14 (see FIG. 5). The "irradiation of laser light" refers to the irradiation of the first laser light L1.

In the laser processing in FIG. 17 , 7 rows of modified regions 4 are formed in the Z direction inside the object 100. The 7 rows of modified regions 4 are sequentially referred to as "SD1", "SD2", "SD3", "SD4", "SD5", "SD6" and "SD7" (hereinafter the same) from the position farthest from the laser light incident surface. When SD1 to SD3 are formed, the orientation of the beam shape 71 is adjusted toward the first orientation and the second orientation, and when SD4 to SD7 are formed, the longitudinal direction NH of the beam shape 71 is made consistent with the processing advancing direction BD.

In FIG. 17 , time advances in the order of time T1 to T10. The various processes shown in FIG. 17 are implemented after calibration, alignment, and height setting are completed. Calibration is the correction process of various measured values. Alignment is the adjustment process of various parts. Height setting is to photograph the laser light incident surface, move the mounting table 107 relatively in the Z direction in a manner that the reflection of the projected mesh pattern is maximized, and use the Z direction position of the laser light incident surface at this time as the focal position (displacement is 0 μm). The timing of various processes is based on, for example, the θ information and rotation speed of the mounting table 107. The same is true for the above points in FIG. 17 in FIG. 18 to FIG. 20 .

In the laser processing device 101, various processes can be performed in the order shown in the time chart of Fig. 17. In the example of Fig. 17, the mounting table 107 does not rotate continuously in one direction of the θ direction (rotation direction around the rotation axis C), but rotates in one direction and the other direction of the θ direction.

Specifically, in the laser processing device 101, as shown in FIG. 17 , tracking processing is performed until time T1. Until time T1, the stage 107 is accelerated in a rotational direction in one direction. The processing position in the Z direction is used as the laser light incident surface, and tracking control is stopped. The orientation of the beam shape 71 is switched to the first orientation. The irradiation of the first laser light L1 is stopped. At time T2, tracking processing is continued. At time T2, the stage 107 is rotated at a constant speed in one direction, and displacement data of the laser light incident surface is obtained by tracking control. The processing content of time T2 is the same as that of time T1.

At time T3, tracking processing is continued. At time T3, the rotation of the stage 107 in one direction is decelerated, and the processing position in the Z direction is moved toward the processing position when SD1 is formed, and the tracking control is stopped. The processing content of time T3 is the same as the processing content of time T2. At time T4, laser processing (SD1 processing) for SD1 formation is performed. At time T4, the rotation direction of the stage 107 in the other direction is accelerated. The processing content of time T4 is the same as the processing content of time T3.

At time T5, SD1 processing is continued. At time T5, the stage 107 is rotated at a constant speed in the other direction, and the driving unit 18 (refer to FIG. 5) is driven. By tracking control, the focusing unit 14 is allowed to track the laser light incident surface. At time T5, the processing position in the Z direction is the processing position when SD1 is formed, and the orientation of the beam shape 71 is the first orientation. The first area M31 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the second area M32 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped.

At time T6, the SD1 processing is continued. At time T6, the rotation of the stage 107 in the other direction is decelerated, the tracking control is stopped, the beam shape 71 is switched to the second direction, and the irradiation of the first laser light L1 is stopped. At time T6, the processing position in the Z direction is the processing position when SD1 is formed. At time T7, the SD1 processing is continued. At time T7, the rotation direction of the stage 107 in one direction is accelerated. The processing content of time T7 is the same as the processing content of time T6.

At time T8, SD1 processing is continued. At time T8, the stage 107 is rotated in one direction at a constant speed, and the driving unit 18 (refer to FIG. 5) is driven. By tracking control, the focusing unit 14 is allowed to track the laser light incident surface. At time T8, the processing position in the Z direction is the processing position when SD1 is formed, and the orientation of the beam shape 71 is the second orientation. The second area M32 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the first area M31 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped.

At time T9, the SD1 process is continued. At time T9, the rotation speed of the stage 107 in one direction is decelerated, and the processing position in the Z direction is moved toward the processing position when SD2 is formed, and the tracking control is stopped. At time T9, the beam shape 71 is switched to the first direction, and the irradiation of the first laser light L1 is stopped.

At time T10, laser processing for SD2 formation (SD2 processing) is performed. At time T10, the stage 107 is accelerated in the other rotational direction. The processing contents at time T10 are otherwise the same as those at time T9. Thereafter, the same processing is repeated until the laser processing is completed.

Furthermore, constant speed includes the meaning of approximately constant speed. The rotation speed may be different between the constant speed rotation of the tracking process and the constant speed rotation when the modified area 4 is formed. The constant speed rotation when the modified area 4 is formed is a rotation with a constant processing speed (pulse interval). Laser processing during constant speed rotation can be started from a position of a specified coordinate (for example, a position in the θ direction where a cut is provided) after the constant speed rotation. During the period of deceleration and acceleration of the rotation, the mounting table 107 can be temporarily stopped, and the processing position in the Z direction or the orientation of the beam shape 71 can be changed during the stop. These conditions are also the same in the following description.

Fig. 18 is a timing chart showing a specific second operation example of laser processing performed by the laser processing apparatus 101 of Fig. 9. In the laser processing apparatus 101, various processes can be performed in the order shown in the timing chart of Fig. 18. In the example of Fig. 18, the stage 107 does not rotate continuously in one direction of the θ direction, but rotates in one direction and the other direction of the θ direction.

As shown in FIG. 18 , SD1 processing is performed until time T1. When time T1 is reached, the stage 107 is accelerated in a rotational direction in one direction. The processing position in the Z direction is used as the processing position when SD1 is formed, and the tracking control is stopped. The beam shape 71 is switched to the first orientation. The irradiation of the first laser light L1 is stopped.

At time T2, SD1 processing is continued. At time T2, the stage 107 is rotated in one direction at a constant speed, and the driving unit 18 (refer to FIG. 5) is driven. By tracking control, the focusing unit 14 is allowed to track the laser light incident surface. At time T2, the processing position in the Z direction is the processing position when SD1 is formed, and the orientation of the beam shape 71 is the first orientation. The first area M31 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the second area M32 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped.

At time T3, the SD1 processing is continued. At time T3, the rotation of the stage 107 in one direction is decelerated, and the processing position in the Z direction is moved toward the processing position when SD1 is formed, and the tracking control is stopped. At time T3, the beam shape 71 is switched to the second direction, and the irradiation of the first laser light L1 is stopped. At time T4, the SD1 processing is continued. At time T4, the rotation direction of the stage 107 in the other direction is accelerated. The processing content of time T4 is the same as the processing content of time T3.

At time T5, SD1 processing is continued. At time T5, the stage 107 is rotated at a constant speed in the other direction, and the driving unit 18 (refer to FIG. 5) is driven. By tracking control, the focusing unit 14 is allowed to track the laser light incident surface. At time T5, the processing position in the Z direction is the processing position when SD1 is formed, and the orientation of the beam shape 71 is the second orientation. The second area M32 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the first area M31 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped.

At time T6, SD1 processing is continuously performed. At time T6, the rotation of the mounting table 107 in the other direction is decelerated, the processing position in the Z direction is moved toward the processing position when SD2 is formed, the tracking control is stopped, the orientation of the beam shape 71 is switched to the first orientation, and the irradiation of the first laser light L1 is stopped. At time T7, SD2 processing is performed. At time T7, the mounting table 107 is accelerated in the rotation direction in one direction. The processing contents of time T7 other than this are the same as those of time T6. Thereafter, the same processing is repeated until the laser processing is completed. Furthermore, in the tracking control at time T2 of FIG. 18, the tracking action is performed when the length measuring range is long, but the recording or reproducing action may also be performed when the length measuring range is narrow.

Fig. 19 is a timing chart showing a specific third operation example of laser processing performed by the laser processing apparatus 101 of Fig. 9. In the laser processing apparatus 101, various processes can be performed in the order shown in the timing chart of Fig. 19. In the example of Fig. 19, the stage 107 rotates continuously in one direction or the other direction of the θ direction.

As shown in FIG. 19 , tracking processing is performed until time T1. When time T1 is reached, the stage 107 is accelerated. The processing position in the Z direction is used as the laser light incident surface, and tracking control is stopped. The orientation of the beam shape 71 is switched to the first orientation. The irradiation of the first laser light L1 is stopped. At time T2, tracking processing is continued. At time T2, the stage 107 is rotated at a constant speed, and the displacement data of the laser light incident surface is obtained by tracking control. The processing content of time T2 is the same as that of time T1.

At time T3, tracking processing is continued. At time T3, the rotation of the mounting table 107 is maintained, and the processing position in the Z direction is moved toward the processing position when SD1 is formed, and the tracking control is stopped. The processing content of time T3 is the same as the processing content of time T2. At time T4, SD1 processing is performed. At time T4, the mounting table 107 is rotated at a constant speed, and the driving part 18 (refer to Figure 5) is driven. Through tracking control, the focusing part 14 tracks the laser light incident surface. At time T4, the processing position in the Z direction is the processing position when SD1 is formed, and the orientation of the beam shape 71 is the first orientation. The first area M31 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form a modified area 4. In addition, the second region M32 along the line M3 is not irradiated with the first laser light L1 (OFF), and the formation of the modified region 4 is stopped.

At time T5, the SD1 processing is continued. At time T5, the rotation of the stage 107 is maintained, the processing position in the Z direction is set as the processing position when SD1 is formed, the tracking control is stopped, the beam shape 71 is switched to the second direction, and the irradiation of the first laser light L1 is stopped.

At time T6, SD1 processing is continued. At time T6, the stage 107 is rotated at a constant speed to drive the driving unit 18 (see FIG. 5 ), and the focusing unit 14 is controlled to follow the laser light incident surface. At time T6, the processing position in the Z direction is the processing position when SD1 is formed, and the orientation of the beam shape 71 is the second orientation. The second area M32 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the first area M31 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped.

At time T7, the SD1 process is continued. At time T7, the rotation of the stage 107 is maintained, the process position in the Z direction is moved toward the process position when SD2 is formed, and the tracking control is stopped. At time T7, the beam shape 71 is switched to the first direction, and the irradiation of the first laser light L1 is stopped.

At time T8, SD2 processing is performed. At time T8, the stage 107 is rotated at a constant speed to drive the driving unit 18 (see FIG. 5 ), and the focusing unit 14 is controlled to follow the laser light incident surface by tracking. At time T8, the processing position in the Z direction is the processing position when SD2 is formed, and the orientation of the beam shape 71 is the first orientation. The first area M31 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the second area M32 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped. Thereafter, the same process is repeated until the laser processing is completed.

Furthermore, the rotation speed may be non-constant or variable during the rotation during the time periods T3, T5, and T7, that is, as long as the rotation does not stop. If the time required to switch the orientation of the beam shape 71 during the rotation during the time periods T3, T5, and T7 is long, the stage 107 may be rotated twice or more during this period. The same applies to the following description.

Fig. 20 is a timing chart showing a specific fourth operation example of laser processing performed by the laser processing apparatus 101 of Fig. 9. In the laser processing apparatus 101, various processes can be performed in the order shown in the timing chart of Fig. 20. In the example of Fig. 20, the stage 107 continuously rotates in one direction or the other direction of the θ direction.

As shown in FIG. 20 , SD1 processing is performed until time T1. When time T1 is reached, the stage 107 is accelerated. The processing position in the Z direction is set as the processing position when SD1 is formed, and the tracking control is stopped. The beam shape 71 is switched to the first orientation. The irradiation of the first laser beam L1 is stopped.

At time T2, SD1 processing is continued. At time T2, the stage 107 is rotated at a constant speed to drive the driving unit 18 (see FIG. 5 ), and the focusing unit 14 is controlled to follow the laser light incident surface by tracking. At time T2, the processing position in the Z direction is the processing position when SD1 is formed, and the orientation of the beam shape 71 is the first orientation. The first area M31 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the second area M32 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped.

At time T3, the SD1 processing is continued. At time T3, the rotation of the stage 107 is maintained, the processing position in the Z direction is set as the processing position when SD1 is formed, and the tracking control is stopped. At time T3, the beam shape 71 is switched to the second direction, and the irradiation of the first laser light L1 is stopped.

At time T4, SD1 processing is continued. At time T4, the stage 107 is rotated at a constant speed in the other direction, and the driving unit 18 (refer to FIG. 5) is driven. By tracking control, the focusing unit 14 is allowed to track the laser light incident surface. At time T4, the processing position in the Z direction is the processing position when SD1 is formed, and the orientation of the beam shape 71 is the second orientation. The second area M32 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the first area M31 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped.

At time T5, SD1 processing is continued. At time T6, the processing position in the Z direction is moved toward the processing position when SD2 is formed while maintaining the rotation of the stage 107, the tracking control is stopped, the beam shape 71 is switched to the first orientation, and the irradiation of the first laser light L1 is stopped.

At time T6, SD2 processing is performed. At time T6, the stage 107 is rotated at a constant speed to drive the driving unit 18 (see FIG. 5 ), and the focusing unit 14 is controlled to follow the laser light incident surface by tracking. At time T6, the processing position in the Z direction is the processing position when SD2 is formed, and the orientation of the beam shape 71 is the first orientation. The first area M31 along the line M3 is irradiated (ON) with the first laser light L1 and the first focusing point P1 is moved to form the modified area 4. In addition, the second area M32 along the line M3 is not irradiated (OFF) with the first laser light L1, and the formation of the modified area 4 is stopped. Thereafter, the same process is repeated until the laser processing is completed.

Incidentally, in the first to fourth operation examples, after the modified region 4 is formed along the first region M31 of the line M3, the modified region 4 is formed along the second region M32 of the line M3. However, the modified region 4 may be formed along the second region M32 and then the modified region 4 may be formed along the first region M31. Furthermore, after the modified region 4 by SD1 is formed along the second region M32, the modified region 4 by SD2 may be formed along the second region M32, and the modified region 4 by SD2 may be formed along the first region M31. Furthermore, after forming a modified region 4 by SD1 along the first region M31 and a modified region 4 by SD2 along the first region M31, a modified region 4 by SD1 along the second region M32 and a modified region 4 by SD2 along the second region M32 may be formed.

FIG. 21(a) is a photograph showing a portion of the object 100 after trimming processing in which the longitudinal direction NH of the beam shape 71 is aligned with the processing advancing direction BD. FIG. 21(b) is a photograph showing a portion of the object 100 after trimming processing by the laser processing device 101 of FIG. 9. The photographs of FIG. 21(a) and FIG. 21(b) show trimming surfaces of cross-sectional views cut with the modified region 4 formed in the first region M31 of the object 100 along the line M3 as a boundary. In the laser processing in FIG. 21(a) and FIG. 21(b), the modified region 4 is formed in 7 rows in the Z direction on the object 100.

In FIG. 21(a), when SD1 to SD7 are formed, the longitudinal direction NH of the beam shape 71 is made consistent with the processing direction BD. In FIG. 21(b), when SD1 to SD3 are formed, the orientation of the beam shape 71 is adjusted to the first orientation in the first processing step, and when SD4 to SD7 are formed, the longitudinal direction NH of the beam shape 71 is made consistent with the processing direction BD. The object 100 is a mirror wafer formed of silicon with a thickness of 775 μm. The object 100 has a (100) plane as the main surface and a resistivity of 1Ω･cm. The laser light incident surface is the back surface 100b, and the distance from the surface 100a to SD1 is 60 μm.

From the comparison between Figure 21(a) and Figure 21(b), it can be seen that when the modified area 4 is formed in the first area M31 along the line M3, it is confirmed that by adjusting the orientation of the beam shape 71 in the processing direction BD to the first orientation, the twisted comb pattern reaching the surface 100a from SD1 can be suppressed, thereby suppressing quality deterioration.

Fig. 22(a) is a photograph showing a portion of the object 100 after trimming processing in which the longitudinal direction NH of the beam shape 71 is aligned with the processing advancing direction BD. Fig. 22(b) is a photograph showing a portion of the object 100 after trimming processing by the laser processing device 101 of Fig. 9. The photographs of Fig. 22(a) and Fig. 22(b) show trimmed surfaces of cross-sectional views cut with the modified region 4 formed in the second region M32 of the object 100 along the line M3 as a boundary.

In FIG. 22(a), when SD1 to SD7 are formed, the longitudinal direction NH of the beam shape 71 is made consistent with the processing direction BD. In FIG. 22(b), when SD1 to SD3 are formed, the orientation of the beam shape 71 is adjusted to the second orientation in the second processing step, and when SD4 to SD7 are formed, the longitudinal direction NH of the beam shape 71 is made consistent with the processing direction BD. The object 100 is a mirror wafer formed of silicon with a thickness of 775 μm. The object 100 has a (100) plane as the main surface and a resistivity of 1Ω･cm. The laser light incident surface is the back surface 100b, and the distance from the surface 100a to SD1 is 60 μm.

From the comparison between Figure 22(a) and Figure 22(b), it can be seen that when the modified area 4 is formed in the second area M32 along the line M3, it is confirmed that adjusting the orientation of the beam shape toward the processing direction BD to the second orientation can suppress the twisted comb pattern from SD1 to the surface 100a, thereby suppressing quality deterioration.

Fig. 23 is a diagram showing a portion of the trimmed object 100. The photograph of Fig. 23 shows a trimmed surface of a cross-sectional view cut with the modified region 4 formed along the line M3 in the object 100 as a boundary. The photographs of Figure 23 show the results of the following situations, namely, when forming the modified regions 4 of the entire row (SD1~SD7), the beam angle β is set to 0°; when forming the modified region 4 of SD1, the beam angle β is set to +15° and when forming other modified regions 4, the beam angle β is set to 0°; when forming the modified regions 4 of SD1 and SD2, the beam angle β is set to +15° and when forming other modified regions 4, the beam angle β is set to 0°; and when forming the modified regions 4 of SD1~SD3, the beam angle β is set to +15° and when forming other modified regions 4, the beam angle β is set to 0°.

As shown in FIG. 23 , it was confirmed that when the beam angle β was set to 0° when forming a full row of modified regions 4, the processing quality deteriorated, and the more the number of rows of modified regions 4 formed by adjusting the beam angle β increased, the better the processing quality became. It was also confirmed that the number of rows of modified regions 4 formed by adjusting the beam angle β was effective starting from 1 row, and that more ideal laser processing could be achieved if the number of rows of modified regions 4 formed by adjusting the beam angle β was 3 rows.

FIG. 24 is a table showing a summary of experimental results of evaluating the processing quality when the beam angle β and the processing angle α are changed. FIG. 25 to FIG. 54 are photographs of the trimmed surface of each object 100 showing the experimental results of FIG. 24. In this evaluation test, a plurality of rows of modified regions 4 are formed on the object 100. The object 100 is a mirror wafer formed of silicon, with the (100) plane as the main surface and a resistivity of 1Ω･cm. The laser light incident surface is the back surface 100b. In FIG. 24, very good processing quality is indicated as "○", good (roughly good) processing quality is indicated as "△", and deteriorated processing quality is indicated as "×". Twist comb lines are generated under SD1 (modified region 4 at the farthest position from the laser light incident surface), but they do not reach the surface 100a on the opposite side of the laser light incident surface, which is considered to be a good processing quality ("△" in Figure 24).

As shown in Figures 24, 25 and 40, when the processing angle α is 0°, the processing quality is very good when the beam angle β is 5° to 30° and -5° to -30°. As shown in Figures 24, 26 and 41, when the processing angle α is 5°, the processing quality is very good when the beam angle β is 10° to 35°.

As shown in Figures 24, 27 and 42, when the processing angle α is 10°, the processing quality is very good when the beam angle β is 10° to 35°. As shown in Figures 24, 28 and 43, when the processing angle α is 15°, the processing quality is very good when the beam angle β is 5° to 10° and 20°.

As shown in Figures 24, 29 and 44, when the processing angle α is 20°, the processing quality is very good when the beam angle β is 0° to 35°. As shown in Figures 24, 30 and 45, when the processing angle α is 22.5°, the processing quality is very good when the beam angle β is -5° to 30°.

As shown in Figures 24, 31 and 46, when the processing angle α is 25°, the processing quality is very good when the beam angle β is 0° to 30°. As shown in Figures 24, 32 and 47, when the processing angle α is 30°, the processing quality is very good when the beam angle β is 0° to 10° and 22° to 25°.

As shown in Figures 24, 33 and 48, when the processing angle α is 35°, the processing quality is very good when the beam angle β is 0° to 22°. As shown in Figures 24, 34 and 49, when the processing angle α is 40°, the processing quality is very good when the beam angle β is 0° to 10°.

As shown in Figures 24, 35 and 50, when the processing angle α is 45°, the processing quality is very good when the beam angle β is -5° to 10°, -15° and -22°. As shown in Figures 24, 36 and 51, when the processing angle α is 50°, the processing quality is very good when the beam angle β is -5° to 0°, -15° and -22°.

As shown in Figures 24, 37 and 52, when the processing angle α is 55°, the processing quality is very good when the beam angle β is -30° to 0° and -5°. As shown in Figures 24, 38 and 53, when the processing angle α is 80°, the processing quality is very good when the beam angle β is -35° to -15°. As shown in Figures 24, 39 and 54, when the processing angle α is 85°, the processing quality is very good when the beam angle β is -35° to -10°.

As shown in the results of Figures 24 to 54, it is known that when the longitudinal direction NH of the beam shape 71 is aligned with the processing direction BD, the processing angle α at which the quality is slightly deteriorated is 15° to 30° and 60° to 75°. In this processing angle range (15° to 30° and 60° to 75°), the beam angle β at which the processing quality improvement effect is particularly significant is 0° to 35°. In addition, it is known that when the longitudinal direction NH of the beam shape 71 is aligned with the processing direction BD, the processing angle α at which the quality is particularly rapidly deteriorated is 5° to 15° and 75° to 85°. In this processing angle range (5° to 15° and 75° to 85°), the beam angle β at which the processing quality improvement effect is particularly significant is 10° to 35° and -35° to -10°.

When the processing angle α is between 0° and 45°, the processing quality improvement at 5° to 15° of the processing angle α where the quality deterioration is particularly rapid is particularly important, so the beam angle β is preferably set to 10° to 35°, where the improvement effect is particularly significant. When the processing angle α is between 45° and 90°, the processing quality improvement at 75° to 85° of the processing angle α where the quality deterioration is particularly rapid is particularly important, so the beam angle β is preferably set to -35° to -10°, where the improvement effect is particularly significant.

[Second embodiment] Next, the laser processing device of the second embodiment is described. In the description of the second embodiment, the differences from the first embodiment are described, and the descriptions repeated in the first embodiment are omitted.

The processing control unit 9c of this embodiment performs a circumferential processing, which forms a ring-shaped modified area 4 along the line M3 by relatively moving the first focal point P1 along the line M3 on the object 100. In the circumferential processing, the first laser light L1 is irradiated while the stage 107 is rotated so that the first focal point P1 is located at a predetermined position in the Z direction of the object 100. When the irradiation of the first laser light L1 starts and the stage 107 rotates one circle (rotates 360 degrees), the irradiation is stopped, thereby forming a ring-shaped modified area 4 along the line M3.

The adjustment unit 9d of this embodiment adjusts the orientation of the longitudinal direction NH to the orientation determined by the determination unit 9b while the first light-converging point P1 is relatively moved along the line M3. Specifically, when the process control unit 9c performs the circumferential process and relatively moves the first light-converging point P1 by one circle along the line M3, the adjustment unit 9d instantly switches the orientation of the longitudinal direction NH to the first orientation when the first light-converging point P1 is located in the first area M31 (refer to FIG. 55(b) and FIG. 57(b)), and instantly switches the orientation of the longitudinal direction NH to the second orientation when the first light-converging point P1 is located in the second area M32 (refer to FIG. 56(b) and FIG. 58(b)).

In the laser processing apparatus 101 of the present embodiment, for example, the trimming process described below is performed.

As shown in FIG. 55(a), the first laser light L1 is irradiated while the stage 107 is rotated, and the first focal point P1 is relatively moved along the first area M31 of the line M3. Thus, the modified area 4 is formed along the first area M31 at a predetermined position in the Z direction of the object 100. At this time, the orientation of the beam shape 71 is adjusted to the first orientation shown in FIG. 55(b) by the adjusting section 9d.

When the first focal point P1 moves from the first area M31 to the second area M32, the orientation of the beam shape 71 is adjusted to the second orientation as shown in FIG. 56(b) by the adjusting section 9d (adjustment process). As shown in FIG. 56(a), the first laser light L1 is continuously irradiated while the stage 107 is rotated, and the first focal point P1 is relatively moved along the second area M32 of the line M3. In this way, the modified area 4 is formed along the second area M32 at a predetermined position in the Z direction of the object 100.

When the first focal point P1 moves from the second region M32 toward the first region M31, the orientation of the beam shape 71 is adjusted to the first orientation as shown in FIG. 57(b) by the adjusting section 9d (adjustment process). As shown in FIG. 57(a), the first laser light L1 is continuously irradiated while the stage 107 is rotated, and the first focal point P1 is relatively moved along the first region M31 of the line M3. In this way, the modified region 4 is formed along the first region M31 at a predetermined position in the Z direction of the object 100.

When the first focal point P1 moves from the first area M31 to the second area M32, the orientation of the beam shape 71 is adjusted to the second orientation as shown in FIG. 58(b) by the adjusting section 9d (adjustment process). As shown in FIG. 58(a), the first laser light L1 is continuously irradiated while the stage 107 is rotated, and the first focal point P1 is relatively moved along the second area M32 of the line M3. In this way, a modified area 4 is formed along the second area M32 at a predetermined position in the Z direction of the object 100. After the movement of the first focal point P1 along the first area M31 and the second area M32 is repeated from the start of irradiation with the first laser light L1 until the stage 107 rotates one circle (rotates 360°), the irradiation is stopped.

The Z-direction position of the predetermined trimming position is changed, and the aforementioned laser processing is repeated. In the above manner, a plurality of rows of modified regions 4 are formed in the Z-direction along the line M3 of the periphery of the effective region R inside the object 100.

As described above, in the laser processing device 101 of the present embodiment, while the first light-converging point P1 is relatively moved along the line M3, the orientation of the longitudinal direction NH of the beam shape 71 is adjusted to an orientation intersecting with the processing travel direction BD, that is, an orientation determined based on the object information and the line information. Therefore, only when the longitudinal direction NH is consistent with the processing travel direction BD, the first light-converging point P1 is relatively moved along the line M3, so that even if the quality of the trimmed surface is degraded depending on the part due to the physical properties of the object 100, the degraded quality of the trimmed surface can be suppressed. Therefore, it is possible to suppress the degraded quality of the trimmed surface of the object 100 from which the outer edge portion, that is, the removed area E, depending on the part.

In particular, in this embodiment, the modified area 4 can be formed along the line M3 while the orientation of the longitudinal direction NH can be instantly changed to an orientation determined based on the object information and the line information. This can improve the technique while suppressing the degradation of the quality of the finished surface.

In the laser processing device 101 of the present embodiment, the determination unit 9b determines the first orientation, which is the orientation of the longitudinal direction NH when the first light-converging point P1 is relatively moved along the first area M31 of the line M3, and the second orientation, which is the orientation of the longitudinal direction NH when the first light-converging point P1 is relatively moved along the second area M32 of the line M3. The adjustment unit 9d adjusts the orientation of the longitudinal direction NH to the first orientation when the first light-converging point P1 is located in the first area M31 during the period of relatively moving the first light-converging point P1 along the line M3. The adjustment unit 9d adjusts the orientation of the longitudinal direction NH to the second orientation when the first light-converging point P1 is located in the second area M32. Thereby, it is possible to more reliably suppress the degradation of the quality of the trimmed surface of the object 100 in the first area M31 and the second area M32.

In the laser processing method using the laser processing device 101, while the first focal point P1 is relatively moved along the line M3, the orientation of the longitudinal direction NH of the beam shape 71 is adjusted to an orientation that intersects with the processing direction BD, that is, an orientation determined based on the object information and the line information. Therefore, only when the longitudinal direction NH is consistent with the processing direction BD, the first focal point P1 is relatively moved along the line M3, so that even if the quality of the trimmed surface is reduced depending on the part due to the physical properties of the object 100, the reduction in the quality of the trimmed surface can be suppressed. Therefore, it is possible to suppress the situation that the quality of the trimmed surface of the object 100 from which the outer edge portion, that is, the area E, is removed, is reduced depending on the part.

By the way, in the present embodiment, the time point for switching the orientation of the beam shape 71 is when the point at which the line M3 intersects the second crystal orientation K2 orthogonally is taken as the 0° point, and the points at 0°, 45°, 90°, 135°, 180° and 225° of the line M3 and the first focal point P1 are located near the point. In this way, the orientation of the beam shape 71 can be switched at a time point when the influence of the beam angle β makes it difficult to achieve processing quality.

The switching of the orientation of the beam shape 71 is performed in such a manner that the beam angle β does not change by more than ±35°. That is, when changing the orientation of the beam shape 71, there are two cases where the beam shape 71 is rotated in the clockwise direction and the beam shape 71 is rotated in the counterclockwise direction. In the example of FIG. 59(a), when the beam shape 71 is rotated in the clockwise direction, the beam angle β does not change by more than ±35°. This is because, as in the example of FIG. 59(b), if the orientation of the beam shape 71 is switched by changing the beam angle β by more than ±35°, the processing quality will deteriorate. Furthermore, when using the reflective spatial light modulator 34 to switch the orientation of the beam shape 71, since the beam angle β changes instantaneously, the switching of the aforementioned beam angle β may not be restricted.

[Third embodiment] Next, the laser processing device of the third embodiment is described. In the description of the third embodiment, the differences from the second embodiment are described, and the descriptions repeated with the second embodiment are omitted.

The determination unit 9b of this embodiment determines the orientation of the longitudinal direction NH when the first focal point P1 is relatively moved along the line M3 at each processing angle α based on the object information and line information obtained by the acquisition unit 9a. As an example, the determination unit 9b determines the orientation of the longitudinal direction NH to be the orientation of the direction inclined to the processing direction BD and the orientation of the direction corresponding to the processing angle α in such a manner that the first crystal orientation K1 and the second crystal orientation K2 are close to the one with a larger angle with the processing direction BD. The determination unit 9b determines the orientation of the longitudinal direction NH to be the orientation of the direction inclined to the processing direction BD and the orientation of the direction corresponding to the processing angle α when the processing angle α is greater than 0° and less than 22.5°. When the processing angle α is greater than 22.5° and less than 45°, the orientation of the longitudinal direction NH is determined so that the beam angle β on the positive side decreases as the processing angle α increases. When the processing angle α is greater than 45° and less than 67.5°, the orientation of the longitudinal direction NH is determined so that the beam angle β increases toward the negative side as the processing angle α increases. When the processing angle α is greater than 67.5° and less than 90°, the orientation of the longitudinal direction NH is determined so that the beam angle β on the negative side decreases as the processing angle α increases (the beam angle β approaches 0).

The adjustment unit 9d of this embodiment adjusts the orientation of the longitudinal direction NH in a continuously changing manner while the first focal point P1 is relatively moved along the line M3. The adjustment unit 9d continuously changes the orientation determined by the determination unit 9b in accordance with the processing angle α while the first focal point P1 is relatively moved along the line M3.

In the laser processing apparatus 101 of the present embodiment, for example, the trimming process described below is performed.

The determination unit 9b determines the orientation of the longitudinal direction NH when the first focal point P1 is relatively moved along the line M3 for each processing angle α according to the processing angle α (determination process). The first laser light L1 is irradiated while the stage 107 is rotated, and the first focal point P1 is relatively moved along the line M3. In this way, the modified area 4 is formed along the line M3 at a predetermined position in the Z direction of the object 100.

At this time, the orientation of the longitudinal direction NH is continuously changed to an orientation determined in accordance with the processing angle α (adjustment process). As shown in FIG. 60(a) and FIG. 60(b), for example, when the processing angle α is 0° (when the first focal point P1 is located at point Q1 at 0° of line M3), the orientation of the beam shape 71 is adjusted to an orientation where the beam angle β is 0°. As shown in FIG. 61(a) and FIG. 61(b), for example, when the processing angle α is 5° to 15° (when the first focal point P1 is located at point Q2 at 5° to 15° of line M3), the orientation of the beam shape 71 is adjusted to an orientation where the beam angle β is 10° to 35°.

As shown in FIG. 62(a) and FIG. 62(b), for example, when the processing angle α is 45° (when the first light-converging point P1 is located at point Q3 of 0° on line M3), the orientation of the beam shape 71 is adjusted to an orientation where the beam angle β is 0°. When the processing angle α is 45°, since the tortoise-crack extension force by the first crystal orientation K1 and the tortoise-crack extension force by the second crystal orientation K2 are balanced (pulled together), it is not necessary to tilt the orientation of the beam shape 71 from the processing advancing direction BD.

As shown in Figures 63(a) and 63(b), for example, when the processing angle α is 75° to 85° (when the first focal point P1 is located at point Q4 at 75° to 85° of line M3), the azimuth of the beam shape 71 is adjusted to a beam angle β of -35° to -10°.

As shown in FIG. 64 (a) and FIG. 64 (b), for example, when the processing angle α is 90° (when the first light-converging point P1 is located at point Q5 at 90° of line M3), the azimuth of the beam shape 71 is adjusted to a azimuth where the beam angle β is 0°. The movement of the first light-converging point P1 along line M3 is repeated from the start of irradiation with the first laser light L1 until the stage 107 rotates once (rotates 360°), and then the irradiation is stopped.

The Z-direction position of the predetermined trimming position is changed, and the aforementioned laser processing is repeated. In the above manner, a plurality of rows of modified regions 4 are formed in the Z-direction along the line M3 of the periphery of the effective region R inside the object 100.

As described above, in the laser processing apparatus 101 of the present embodiment, it is also possible to suppress the situation in which the quality of the trimmed surface of the object 100 where the outer edge portion, that is, the removal area E, is removed is degraded depending on the location.

In the laser processing device 101 of the present embodiment, the adjustment section 9d adjusts the orientation in the longitudinal direction NH in a continuously changing manner while relatively moving the first focal point P1 along the line M3. This can more reliably suppress the quality degradation of the trimmed surface of the object 100 at each portion of the line M3.

In the laser processing device 101 of the present embodiment, the object is a wafer having the (100) plane as the main surface and having a first crystal orientation K1 and a second crystal orientation K2. The determining section 9b determines the orientation in the length direction NH when the first focal point P1 is relatively moved along the line M3 for each processing angle α. The adjusting section 9d continuously changes the orientation determined by the determining section 9b in accordance with the processing angle α while the first focal point P1 is relatively moved along the line M3. Thus, even when the object 100 is a wafer having the (100) plane as the main surface, it is possible to more reliably suppress the quality of the trimmed surface of the object 100 from being reduced at various locations on the line M3.

[Fourth Implementation] Next, the laser processing device of the fourth implementation will be described. In the description of the fourth implementation, the differences from the third implementation will be described, and the descriptions that are repeated with the third implementation will be omitted.

As shown in FIG. 65 , the line M3 includes the first part M3A, the second part M3B, and the third part M3C. The first part M3A is a point where the line M3 intersects the second crystal orientation K2 orthogonally as the 0° point, and includes the part between the 5° point and the 15° point, the part between the 95° point and the 105° point, the part between the 185° point and the 195° point, and the part between the 275° point and the 285° point. The second part M3B is a part of the line M3 separated from the first part M3A. The second portion M3B is a portion from the point of 75° to the point of 85°, a portion from the point of 145° to the point of 175°, a portion from the point of 55° to the point of 85°, and a portion from the point of 55° to the point of 85°, with the point at which the line M3 intersects the second crystal orientation K2 at right angles as the 0° point. The third portion M3C is a portion located between the first portion M3A and the second portion M3B.

The determination unit 9b of this embodiment determines the orientation of the length direction NH of the first part M3A to be the first orientation based on the object information and line information obtained by the acquisition unit 9a, so that the length direction NH intersects with the processing direction BD. The determination unit 9b determines the orientation of the length direction NH of the second part M3B to be the second orientation based on the object information and line information, so that the length direction NH intersects with the processing direction BD.

The adjustment section 9d of this embodiment adjusts the orientation of the first portion M3A in the longitudinal direction NH to be the determined first orientation. The adjustment section 9d of this embodiment adjusts the orientation of the second portion M3B in the longitudinal direction NH to be the determined second orientation. The adjustment section 9d changes the orientation of the longitudinal direction NH from the first orientation to the second orientation at the third portion M3C of the line M3 by relatively moving the first focal point P1 along the first portion M3A and then relatively moving the first focal point P1 along the second portion M3B.

In the laser processing apparatus 101 of the present embodiment, for example, the trimming process described below is performed.

Based on the object information and the line information, the determining unit 9b determines the orientation of the first portion M3A of the line M3 in the longitudinal direction NH to be the first orientation, and determines the orientation of the second portion M3B of the line M3 in the longitudinal direction NH to be the second orientation.

The orientation of the longitudinal direction NH is adjusted to the first orientation by the adjusting section 9d (see FIG. 66(b)). As shown in FIG. 66(a), the first laser light L1 is irradiated while the stage 107 is rotated, and the first focal point P1 of the beam shape 71 whose orientation in the longitudinal direction NH is the first orientation is relatively moved along the first portion M3A of the line M3. In this way, the modified region 4 is formed along the first portion M3A at a predetermined position in the Z direction of the object 100.

As shown in FIG. 67(a), the first laser light L1 is continuously irradiated while the stage 107 is rotated, and the first focal point P1 is relatively moved along the third portion M3C of the line M3. Thus, the modified region 4 is formed along the third portion M3C of the line M3 at a predetermined position in the Z direction of the object 100. While the modified region 4 is being formed along the third portion M3C, as shown in FIG. 67(b), the orientation in the longitudinal direction NH is changed from the first orientation to the second orientation by the adjustment portion 9d.

Next, as shown in FIG. 68( a), the first laser light L1 is continuously irradiated while the stage 107 is rotated, and the first focal point P1 of the beam shape 71 whose orientation in the longitudinal direction NH is the second orientation is relatively moved along the second portion M3B of the line M3. Thus, a modified region 4 is formed along the second portion M3B at a predetermined position in the Z direction of the object 100.

Next, the first laser beam L1 is continuously irradiated while the stage 107 is rotated, and the first focal point P1 is relatively moved along the third portion M3C of the line M3. Thus, the modified region 4 is formed along the third portion M3C of the line M3 at a predetermined position in the Z direction of the object 100. While the modified region 4 is being formed along the third portion M3C, the orientation in the longitudinal direction NH is changed from the second orientation to the first orientation by the adjustment portion 9d.

The movement of the first focal point P1 along the line M3 is repeated from the start of the irradiation of the first laser light L1 until the stage 107 rotates one circle (rotates 360 degrees), and then the irradiation is stopped. The Z direction position of the trimming predetermined position is changed, and the above laser processing is repeated. In the above manner, a plurality of rows of modified areas 4 are formed in the Z direction along the line M3 of the periphery of the effective area R inside the object 100.

In the laser processing device 101 of the present embodiment, the first focal point P1 is relatively moved along the line M3 in the first portion M3A of the line M3 in a state where the longitudinal direction NH of the beam shape 71 intersects with the processing direction BD. Thus, for example, only in a state where the longitudinal direction NH of the beam shape 71 coincides with the processing direction BD, the first focal point P1 is relatively moved along the line M3, so that even if the quality of the trimmed surface of the first portion M3A of the line M3 is degraded due to the physical properties of the object 100, the deterioration of the quality of the trimmed surface can be suppressed. Therefore, according to the laser processing device 101 of the present embodiment, it is possible to suppress the deterioration of the quality of the trimmed surface of the object 100 from which the removal area E as the outer edge portion is removed depending on the portion.

In the laser processing device 101 of the present embodiment, the determination unit 9b determines the orientation of the longitudinal direction NH of the second part M3B separated from the first part M3A to be the second orientation based on the object information and line information obtained by the acquisition unit 9a, so that the longitudinal direction NH intersects with the processing direction BD. The adjustment unit 9d adjusts the orientation of the longitudinal direction NH of the second part M3B to become the second orientation determined by the determination unit 9b. In this way, the quality reduction of the trimmed surface of the object 100 in the first part M3A and the second part M3B separated from each other can be more reliably suppressed.

In the laser processing device 101 of the present embodiment, after the first light-converging point P1 is relatively moved along the first portion M3A, the first light-converging point P1 is relatively moved along the second portion M3B, and the adjustment unit 9d changes the orientation of the longitudinal direction NH from the first orientation to the second orientation at the third portion M3C located between the first portion M3A and the second portion M3B. Similarly, after the first light-converging point P1 is relatively moved along the second portion M3B, the first light-converging point P1 is relatively moved along the first portion M3A, and the adjustment unit 9d changes the orientation of the longitudinal direction NH from the second orientation to the first orientation at the third portion M3C located between the second portion M3B and the first portion M3A.

This can more reliably suppress the deterioration of the quality of the trimmed surface of the object 100 in the first part M3A and the second part M3B that are separated from each other. With regard to the beam angle β, the first part M3A and the second part M3B, which are important angle regions, are set to the most appropriate angle, and the third part M3C, which is between the first part M3A and the second part M3B and is not easily affected by the beam angle β, can be switched. It is possible to achieve both technique improvement and higher processing quality.

In the laser processing device 101 of the present embodiment, the object 100 is a wafer having a (100) plane as a main surface, and having a first crystal orientation K1 perpendicular to the (110) plane on one side, and a second crystal orientation K2 perpendicular to the (110) plane on the other side. The line M3 extends in a circular ring shape when viewed from a direction perpendicular to the main surface. When a point at which the line M3 intersects the second crystal orientation K2 is taken as a point of 0°, the first part M3A includes a portion between a point of 5° and a point of 15°. The second part M3B includes a portion between a point of 55° and a point of 85°. Thus, even when the object 100 is a wafer having a (100) plane as a main surface, it is possible to suppress the quality of the trimmed surface of the object 100 from being reduced depending on the location.

In the laser processing device 101 of the present embodiment, the first orientation and the second orientation are orientations in a direction inclined to the processing direction BD in such a manner that the first crystal orientation K1 and the second crystal orientation K2, whichever has a larger angle with the processing direction BD (the further away), are close to each other. Thus, even when the object 100 is a wafer having a (100) plane as a main surface, it is possible to more reliably suppress the degradation of the quality of the trimmed surface of the object 100 in the first part M3A and the second part M3B separated from each other.

In the laser processing device 101 of the present embodiment, the first orientation and the second orientation are orientations inclined by 10° to 35° from the processing direction BD in such a manner that the first crystal orientation K1 and the second crystal orientation K2 are close to the one with a larger angle with the processing direction BD. Thus, even when the object 100 is a wafer with the (100) plane as the main surface, it is possible to more reliably suppress the degradation of the quality of the trimmed surface of the object 100 in the first part M3A and the second part M3B separated from each other.

In the laser processing method of the present embodiment, the first light-converging point P1 is relatively moved along the line M3 in the state where the longitudinal direction NH of the beam shape 71 and the processing direction BD intersect each other in the first part M3A and the second part M3B, respectively. Thus, for example, only in the state where the longitudinal direction NH of the beam shape 71 and the processing direction BD coincide with each other, the first light-converging point P1 is relatively moved along the line M3, so that even if the quality of the trimmed surface of the first part M3A and the second part M3B is degraded due to the physical properties of the object 100, the deterioration of the quality of the trimmed surface can be suppressed. Therefore, it is possible to suppress the deterioration of the quality of the trimmed surface of the object 100 from which the removal area E is removed depending on the part.

[Variations] The above is an aspect of the present invention that is not limited to the aforementioned implementation.

In the aforementioned embodiment, the object information includes information on the crystal orientation of the object 100, but if it is information on the object, it may also include various other information. The object information may also include other information on the physical properties of the object 100, and may further include information on the shape and size of the object 100. In the aforementioned embodiment, the line information includes information on the processing direction BD (moving direction of the focal point) along the line M3, but if it is information on the line M3 in the case of moving the focal point along the line M3, it may also include various other information.

In the aforementioned embodiment, information on the orientation (beam angle β) of the beam shape 71 in the longitudinal direction NH when the first focal point P1 is relatively moved along the line M3 is input to the control unit 9 by user operation or external communication. In this case, the acquisition unit 9a acquires the input information on the orientation in the longitudinal direction NH. The determination unit 9b determines the orientation in the longitudinal direction NH based on the input information. The input orientation in the longitudinal direction NH is information about the line M3 and the object 100 based on the extension direction of the line M3 and the physical properties of the object 100. That is, the input information on the orientation in the longitudinal direction NH can correspond to the object information and the line information. Furthermore, the input orientation of the longitudinal direction NH may be input for each region (part) of the line M3, each processing angle α, or a processing angle region, and may also be input as a numerical value, a range, or an expression.

In the above-mentioned embodiment, when the first light-converging point P1 is relatively moved along N respective regions (portions) of the line M3, the orientation of the longitudinal direction NH can also be determined in the first to Nth orientations (N is an integer greater than 3). Furthermore, when the first light-converging point P1 is relatively moved along the first to Nth regions to form the modified region 4, the orientation of the longitudinal direction NH can be adjusted to the first to Nth orientations.

The above-mentioned embodiment may also include a plurality of laser processing heads as the irradiation section. For example, as shown in FIG. 69 , in addition to the first laser processing head 10A for irradiating the first laser light, a second laser processing head 10B for irradiating the second laser light may be included.

The second laser processing head 10B irradiates the object 100 placed on the mounting table 107 with the second laser light in the Z direction to form a modified area inside the object 100. The second laser processing head 10B is mounted on the second Z-axis track 106B and the X-axis track 108. The second laser processing head 10B can be linearly moved in the Z direction along the second Z-axis track 106B by the driving force of a known driving device such as a motor. The second laser processing head 10B can be linearly moved in the X direction along the X-axis track 108 by the driving force of a known driving device such as a motor. The first laser processing head 10A and the second laser processing head 10B have internal structures that are mirror images of each other via the rotation axis C. Regarding other structures, the second laser processing head 10B is configured similarly to the first laser processing head 10A.

The second Z-axis track 106B is a track extending along the Z direction. The second Z-axis track 106B is mounted on the second laser processing head 10B via the mounting portion 66. The second Z-axis track 106B allows the second laser processing head 10B to move along the Z direction, so that the second focal point of the second laser light moves along the Z direction. The second Z-axis track 106B corresponds to the track of the aforementioned moving mechanism 6 (refer to FIG. 1 ) or the aforementioned moving mechanism 300 (refer to FIG. 8 ). The second Z-axis track 106B constitutes a vertical moving mechanism.

In the case of the first and second laser processing heads 10A and 10B as the irradiation section, in the first process, the first focal point P1 of the first laser light L1 is relatively moved along the first area M31 of the line M3 to form a modified area, and the formation of the modified area in the area other than the first area M31 of the line M3 is stopped. In the second process, the second focal point P1 of the second laser light L1 is relatively moved along the second area M32 of the line M3 to form a modified area, and the formation of the modified area in the area other than the second area M32 of the line M3 is stopped. The adjustment unit 9d adjusts the orientation of the beam shape 71 of the first laser light L1 in the longitudinal direction NH to the first orientation when performing the first processing, and adjusts the orientation of the beam shape of the second laser light in the longitudinal direction to the second orientation when performing the second processing.

In the case of the first and second laser processing heads 10A and 10B as the irradiation section, the first processing and the second processing can be performed in parallel (simultaneously). In this way, the technique can be improved. In the case of the first and second laser processing heads 10A and 10B as the irradiation section, the first processing and the second processing can be performed separately (at different times) in time. In the case of the first and second laser processing heads 10A and 10B as the irradiation section, the first and second laser processing heads 10A and 10B can also play a coordinated role to form a row of modified areas 4 at predetermined positions in the Z direction. In the case of having the first and second laser processing heads 10A and 10B as irradiation sections, a row of modified regions 4 may be formed by the first laser processing head 10A, and a row of modified regions 4 may be formed by the second laser processing head 10B at a different position in the Z direction.

For example, the laser processing device 800 shown in Fig. 70 may include four laser processing heads. The laser processing device 800 is the laser processing device 101 shown in Fig. 69 , and further includes third and fourth laser processing heads 10C, 10D, third and fourth Z-axis tracks 106C, 106D, and a Y-axis track 109.

The third laser processing head 10C irradiates the object 100 placed on the mounting table 107 with the third laser light in the Z direction to form a modified area 4 inside the object 100. The third laser processing head 10C is mounted on the third Z-axis track 106C and the Y-axis track 109. The third laser processing head 10C can be linearly moved in the Z direction along the third Z-axis track 106C by the driving force of a known driving device such as a motor. The third laser processing head 10C can be linearly moved in the Y direction along the Y-axis track 109 by the driving force of a known driving device such as a motor. Regarding other structures, the third laser processing head 10C is constructed in the same manner as the first laser processing head 10A.

The fourth laser processing head 10D irradiates the object 100 placed on the mounting table 107 with the fourth laser light in the Z direction to form a modified area 4 inside the object 100. The fourth laser processing head 10D is mounted on the fourth Z-axis track 106D and the Y-axis track 109. The fourth laser processing head 10D can be linearly moved in the Z direction along the fourth Z-axis track 106D by the driving force of a known driving device such as a motor. The fourth laser processing head 10D can be linearly moved in the Y direction along the Y-axis track 109 by the driving force of a known driving device such as a motor. Regarding other structures, the fourth laser processing head 10D is constructed in the same manner as the first laser processing head 10A. The third laser processing head 10C and the fourth laser processing head 10D have internal structures that are mirror images of each other via the rotation axis C.

The 3rd Z-axis track 106C is a track extending along the Z direction. The 3rd Z-axis track 106C is mounted on the 3rd laser processing head 10C via the mounting portion 865 which is the same as the mounting portion 65. The 3rd Z-axis track 106C moves the 3rd laser processing head 10C along the Z direction and moves the 3rd focal point of the 3rd laser light along the Z direction. The 3rd Z-axis track 106C constitutes a vertical movement mechanism.

The 4th Z-axis track 106D is a track extending along the Z direction. The 4th Z-axis track 106D is mounted on the 4th laser processing head 10D via the mounting portion 866 which is the same as the mounting portion 66. The 4th Z-axis track 106D moves the 4th laser processing head 10D along the Z direction and moves the 4th focal point of the 4th laser light along the Z direction. The 4th Z-axis track 106D constitutes a vertical movement mechanism.

The Y-axis track 109 is a track extending along the Y direction. The Y-axis track 109 is mounted on the 3rd and 4th Z-axis tracks 106C and 106D, respectively. The Y-axis track 109 moves the 3rd laser processing head 10C along the Y direction, so that the 3rd focal point of the 3rd laser light moves along the Y direction. The Y-axis track 109 moves the 4th laser processing head 10D along the Y direction, so that the 4th focal point of the 4th laser light moves along the Y direction. The Y-axis track 109 moves the 3rd and 4th laser processing heads 10C and 10D so that the 3rd and 4th focal points pass through the rotation axis C or its vicinity. The Y-axis track 109 corresponds to the track of the moving mechanism 400 (refer to FIG. 8 ). The Y-axis track 109 constitutes a horizontal movement mechanism. The X-axis track 108 and the Y-axis track 109 are arranged at different heights. For example, the X-axis track 108 is arranged at the lower side and the Y-axis track 109 is arranged at the upper side.

In the aforementioned embodiment, a reflective spatial light modulator 34 is used as a forming part, but the forming part is not limited to the spatial light modulator, and various devices or optical systems can be used. For example, as the forming part, an elliptical beam optical system, a slit optical system, or an astigmatism optical system can be used. In addition, a grating pattern can be used as a modulation pattern to make the focal points diverge and combine more than two focal points to form a beam shape 71 with a length direction NH. In addition, a beam shape 71 with a length direction NH can be formed by using polarized light, and a method of rotating the direction of polarized light can be achieved by, for example, rotating a 1/2λ wavelength plate. In addition, the spatial light modulator is not limited to a reflective type, and a transmissive spatial light modulator can also be used.

In the above-mentioned embodiment, the formation and stop of the modified area 4 are switched by controlling the first laser light L1 or its optical system by the process control unit 9c, but the present invention is not limited thereto. The formation and stop of the modified area 4 can also be achieved by using various known techniques. For example, the formation and stop of the modified area 4 can also be switched by directly setting a mask on the object 100 to shield the first laser light L1.

In the above-mentioned embodiment, the type of the object 100, the shape of the object 100, the size of the object 100, the number and direction of the crystal orientations of the object 100, and the plane orientation of the main surface of the object 100 are not particularly limited. In the above-mentioned embodiment, the shape of the line M3 is not particularly limited. In the above-mentioned embodiment, the determination section 9b may determine only one of the first orientation and the second orientation, and the adjustment section 9d may adjust the orientation of the longitudinal direction NH to the one of the first orientation and the second orientation.

In the aforementioned embodiment, the back side 100b of the object 100 is used as the laser light incident surface, but the surface 100a of the object 100 may also be used as the laser light incident surface. In the aforementioned embodiment, the modified area 4 may also be, for example, a crystallization area, a recrystallization area, or a gettering area formed inside the object 100. The crystallization area is an area that maintains the structure of the object 100 before processing. The recrystallization area is an area that solidifies as a single crystal or multiple crystals when solidifying after temporary evaporation, plasma or melting. The gettering area is an area that exerts a gettering effect to collect and capture impurities such as heavy metals, and may be formed continuously or intermittently. In addition, for example, the processing device may be applicable to processing such as stripping plasma.

The laser processing apparatus of the aforementioned embodiment may not include the acquisition unit 9a. The laser processing method of the aforementioned embodiment may not include a process for acquiring object information and line information (information acquisition process). In this case, for example, the object 100 to be laser processed is determined in advance, and the object information and line information are stored in advance.

The structures of the aforementioned embodiments and modifications are not limited to the aforementioned materials and shapes, and can be applied to various materials and shapes. In addition, the structures of the aforementioned embodiments or modifications can be arbitrarily applied to the structures of other embodiments or modifications.

1,101,800: Laser processing device 4: Modified area 9: Control unit 9a: Acquisition unit 9b: Determination unit 9c: Processing control unit 9d: Adjustment unit 10A: First laser processing head (irradiation unit) 10B: Second laser processing head (irradiation unit) 10C: Third laser processing head (irradiation unit) 10D: Fourth laser processing head (irradiation unit) 34: Reflection type spatial light modulator (shaping unit) 71: Beam shape (shape of a part of the focusing area) 100: Object 100a: Surface ( Main surface) 100b: Inner surface (main surface, laser light incident surface) 107: Support table (support part) K1: First crystal orientation (crystal orientation) K2: Second crystal orientation (crystal orientation) L1: First laser light (laser light) L2: Second laser light (laser light) M3: Line M31: First area (first part) M32: Second area (first part) M3A: First part M3B: Second part M3C: Third part NH: Longitudinal direction P1: First focal point (part of the focal area)

[FIG. 1] is an oblique view of a laser processing device of an embodiment. [FIG. 2] is a front view of a portion of the laser processing device shown in FIG. 1. [FIG. 3] is a front view of a laser processing head of the laser processing device shown in FIG. 1. [FIG. 4] is a side view of the laser processing head shown in FIG. 3. [FIG. 5] is a configuration diagram of an optical system of the laser processing head shown in FIG. 3. [FIG. 6] is a configuration diagram of an optical system of a laser processing head of a modified example. [FIG. 7] is a front view of a portion of a laser processing device of a modified example. [FIG. 8] is an oblique view of a laser processing device of a modified example. [FIG. 9] is a plan view showing a schematic structure of the laser processing device of the first embodiment. [FIG. 10(a)] is a plan view showing an example of an object. [FIG. 10(b)] is a side view of the object shown in FIG. 10(a). [Fig. 11(a)] is a side view of an object to be processed for the first embodiment. [Fig. 11(b)] is a plan view of an object subsequent to Fig. 11(a). [Fig. 11(c)] is a side view of the object shown in Fig. 11(b). [Fig. 12(a)] is a side view of an object subsequent to Fig. 11(b). [Fig. 12(b)] is a plan view of an object subsequent to Fig. 12(a). [Fig. 13(a)] is a plan view of an object subsequent to Fig. 12(b). [Fig. 13(b)] is a side view of an object shown in Fig. 13(a). [Fig. 13(c)] is a side view of an object to be processed for the first embodiment. [FIG. 14] is a plan view of an object to be subjected to trimming processing of the first embodiment. [FIG. 15(a)] is a plan view of an object used to explain the main part of trimming processing of the first embodiment. [FIG. 15(b)] is a diagram showing the beam shape during laser processing of FIG. 15(a). [FIG. 16(a)] is a plan view of an object subsequent to FIG. 15(a). [FIG. 16(b)] is a diagram showing the beam shape during laser processing of FIG. 16(a). [FIG. 17] is a time chart showing the first operation example when laser processing is performed by the laser processing device of FIG. 9. [FIG. 18] is a time chart showing the second operation example when laser processing is performed by the laser processing device of FIG. 9. [Figure 19] is a time chart showing the third operation example of the laser processing performed by the laser processing device of Figure 9. [Figure 20] is a time chart showing the fourth operation example of the laser processing performed by the laser processing device of Figure 9. [Figure 21(a)] is a photograph showing a portion of the object after trimming processing in which the longitudinal direction of the beam shape is aligned with the processing direction. [Figure 21(b)] is a photograph showing a portion of the object after trimming processing by the laser processing device of Figure 9. [Figure 22(a)] is a photograph showing a portion of the object after trimming processing in which the longitudinal direction of the beam shape is aligned with the processing direction. [Figure 22(b)] is a photograph showing a portion of the object after trimming processing by the laser processing device of Figure 9. [Figure 23] is a diagram showing a portion of the object after trimming. [Figure 24] is a table showing the experimental results of evaluating the processing quality when the beam angle and the processing angle are changed. [Figure 25] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 26] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 27] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 28] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 29] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 30] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 31] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 32] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 33] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 34] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 35] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 36] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 37] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 38] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 39] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 40] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 41] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 42] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 43] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 44] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 45] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 46] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 47] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 48] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 49] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 50] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 51] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 52] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 53] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 54] is a photograph of the trimmed surface of the object showing the experimental results of Figure 24. [Figure 55(a)] is a plan view of the object used to illustrate the main part of the trimming process of the second embodiment. [Figure 55(b)] is a diagram showing the beam shape during the laser processing of Figure 55(a). [Figure 56(a)] is a plan view of the object following Figure 55(a). [Figure 56(b)] is a diagram showing the beam shape during the laser processing of Figure 56(a). [Figure 57(a)] is a plan view of the object following Figure 56(a). [Figure 57(b)] is a diagram showing the beam shape during the laser processing of Figure 57(a). [Figure 58(a)] is a plan view of the object following Figure 57(a). [Figure 58(b)] is a diagram showing the beam shape during the laser processing of Figure 58(a). [Figure 59(a)] is a diagram for explaining the switching of the orientation of the beam shape. [Figure 59(b)] is another diagram for explaining the switching of the orientation of the beam shape. [Figure 60(a)] is a plan view of the object for explaining the main part of the trimming processing of the third embodiment. [Figure 60(b)] is a diagram showing the beam shape during the laser processing of Figure 60(a). [Figure 61(a)] is a plane view of the object following Figure 60(a). [Figure 61(b)] is a diagram showing the beam shape during the laser processing of Figure 61(a). [Figure 62(a)] is a plane view of the object following Figure 61(a). [Figure 62(b)] is a diagram showing the beam shape during the laser processing of Figure 62(a). [Figure 63(a)] is a plane view of the object following Figure 62(a). [Figure 63(b)] is a diagram showing the beam shape during the laser processing of Figure 63(a). [Figure 64(a)] is a plane view of the object following Figure 63(a). [Figure 64(b)] is a diagram showing the beam shape during the laser processing of Figure 64(a). [Figure 65] is a plan view of an object to be subjected to the trimming process of the fourth embodiment. [Figure 66(a)] is a partial plan view of an object used to explain the main part of the trimming process of the fourth embodiment. [Figure 66(b)] is a diagram showing the beam shape during the laser processing of Figure 66(a). [Figure 67(a)] is a partial plan view of an object subsequent to Figure 66(a). [Figure 67(b)] is a diagram showing the beam shape during the laser processing of Figure 67(a). [Figure 68(a)] is a partial plan view of an object subsequent to Figure 67(a). [Figure 68(b)] is a diagram showing the beam shape during the laser processing of Figure 68(a). [Figure 69] is a plan view showing the schematic structure of a laser processing device of a modified example. [Figure 70] is a plan view showing the schematic structure of a laser processing device of another modified example. [Figure 71(a)] is a diagram showing the beam shape of the laser light incident surface near the focal point of the first laser light with astigmatism. [Figure 71(b)] is a diagram showing the beam shape between the laser light incident surface near the focal point of the first laser light with astigmatism and the opposite surface. [Figure 71(c)] is a diagram showing the beam shape of the laser light incident surface near the focal point of the first laser light with astigmatism. [Figure 72(a)] is a diagram showing the beam shape of the laser light incident surface near the focal point of the first laser light in the case of using a slit or elliptical optical system. [Figure 72(b)] is a diagram showing the beam shape of the laser light incident surface near the focal point of the first laser light in the case of using a slit or elliptical optical system. [Figure 72(c)] is a diagram showing the beam shape of the laser light incident surface near the focal point of the first laser light in the case of using a slit or elliptical optical system.

4: Improved area

71: Beam shape (shape of part of the spotlight area)

100: Object

100n: Alignment object

BD: Processing direction

K1: 1st crystal orientation (crystallization orientation)

K2: Second crystal orientation (crystallization orientation)

M3: Line

M31: Region 1 (Part 1)

M32: Area 2 (Part 1)

NH: Length direction

Claims (11)

A laser processing device forms a modified area on an object by irradiating a portion of a focusing area with laser light on the object, and is characterized by comprising: a support portion for supporting the object; an irradiation portion for irradiating the object supported by the support portion with the laser light; and a control portion for controlling the support portion and the irradiation portion, wherein the irradiation portion has a shaping portion for shaping the laser light so that the shape of the portion of the focusing area in a plane perpendicular to the optical axis of the laser light has a length direction, and the control portion has a determining portion and an adjusting portion. The determining unit determines the orientation of the longitudinal direction when the part of the light-concentrating area is relatively moved along the line, based on the object information about the object and the line information about the line when the part of the light-concentrating area is relatively moved along the line extending in a ring shape inside the outer edge of the object, so that the longitudinal direction intersects with the moving direction of the part of the light-concentrating area, and the adjusting unit adjusts the orientation of the longitudinal direction during the period of relatively moving the part of the light-concentrating area along the line, so that it becomes the orientation determined by the determining unit. The laser processing device as described in claim 1, wherein the object information includes information about the crystal orientation of the object, and the line information includes information about the moving direction of a part of the focusing area. The laser processing device as described in claim 1, wherein the forming section includes a spatial light modulator, and the adjusting section adjusts the orientation in the longitudinal direction by controlling the spatial light modulator. The laser processing device described in claim 2, wherein the forming section includes a spatial light modulator, and the adjusting section adjusts the orientation in the longitudinal direction by controlling the spatial light modulator. A laser processing device as recited in any one of claims 1 to 4, wherein the determining unit determines a first orientation and a second orientation, the first orientation being the orientation in the longitudinal direction when a part of the light-focusing area is relatively moved along the first area of the line, and the second orientation being the orientation in the longitudinal direction when a part of the light-focusing area is relatively moved along the second area of the line, and the adjusting unit adjusts the orientation in the longitudinal direction to the first orientation when a part of the light-focusing area is located in the first area during the relative movement of the part of the light-focusing area along the line, and adjusts the orientation in the longitudinal direction to the second orientation when a part of the light-focusing area is located in the second area. The laser processing device as described in claim 5, wherein the object is a wafer having a (100) plane as a main plane and having a first crystal orientation perpendicular to the (110) plane on one side and a second crystal orientation perpendicular to the (110) plane on the other side, the line extends in a circular ring shape when viewed from a direction perpendicular to the main plane, the first region includes a region where the angle of the part of the light-concentrating region to the moving direction of the first crystal orientation, i.e., the processing angle, is greater than 0° and less than 45° when a part of the light-concentrating region is relatively moved along the line, and the second region includes a region where the processing angle is greater than 45° and less than 90° when a part of the light-concentrating region is relatively moved along the line. The laser processing device as described in claim 6, wherein the first orientation and the second orientation are orientations of a direction inclined to the moving direction in a manner close to the direction with a larger angle formed between the first crystal orientation and the second crystal orientation and the moving direction. The laser processing device as described in claim 7, wherein the first orientation and the second orientation are orientations inclined by 10° to 35° from the moving direction in a manner close to the direction with a larger angle formed between the first crystal orientation and the second crystal orientation and the moving direction. A laser processing device as described in claim 1, wherein the adjustment section adjusts the orientation of the length direction in a continuously changing manner while relatively moving a portion of the focusing area along the line. The laser processing device as recited in claim 9, wherein the object is a wafer having a (100) plane as a main plane and having a first crystal orientation perpendicular to one (110) plane and a second crystal orientation perpendicular to the other (110) plane, the determination unit determines the orientation in the longitudinal direction when the part of the light-concentrating area is relatively moved along the line for each angle of the moving direction of the part of the light-concentrating area to the first crystal orientation, i.e., each processing angle, and the adjustment unit continuously changes the orientation determined by the determination unit in accordance with the processing angle while the part of the light-concentrating area is relatively moved along the line. A laser processing method is to form a modified area on an object by irradiating a portion of a focusing area with laser light on the object, and is characterized by comprising: a determination process and an adjustment process, wherein the determination process is based on object information about the object and line information about a line extending in a ring shape on the inner side of the outer edge of the object to relatively move the portion of the focusing area. The longitudinal direction of the part of the light-collecting area is adjusted so that the longitudinal direction of the shape of the part of the light-collecting area in a plane perpendicular to the optical axis of the laser light intersects with the moving direction of the part of the light-collecting area. The adjustment process is to adjust the longitudinal direction of the part of the light-collecting area to the determined direction while the part of the light-collecting area is relatively moved along the line.

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